App won't deploy successfully

[krisdock]

Logs:

$ git push heroku master
Enumerating objects: 983, done.
Counting objects: 100% (983/983), done.
Delta compression using up to 8 threads
Compressing objects: 100% (432/432), done.
Writing objects: 100% (983/983), 842.94 KiB | 140.49 MiB/s, done.
Total 983 (delta 528), reused 983 (delta 528)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Ruby app detected
remote: -----> Compiling Ruby/Rack
remote: -----> Using Ruby version: ruby-2.5.3
remote: -----> Installing dependencies using bundler 1.15.2
remote:        Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment
remote:        fatal: not a git repository (or any parent up to mount point /)
remote:        Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
remote:        Fetching gem metadata from https://rubygems.org/........
remote:        Fetching version metadata from https://rubygems.org/..
remote:        Fetching dependency metadata from https://rubygems.org/.
remote:        Fetching i18n 0.8.0
remote:        Fetching minitest 4.7.5
remote:        Fetching multi_json 1.12.1
remote:        Installing multi_json 1.12.1
remote:        Installing minitest 4.7.5
remote:        Installing i18n 0.8.0
remote:        Fetching thread_safe 0.3.5
remote:        Fetching tzinfo 0.3.52
remote:        Installing thread_safe 0.3.5
remote:        Installing tzinfo 0.3.52
remote:        Fetching bson 4.2.1
remote:        Installing bson 4.2.1 with native extensions
remote:        Fetching bson_ext 1.5.1
remote:        Installing bson_ext 1.5.1 with native extensions
remote:        Using bundler 1.15.2
remote:        Fetching chronic 0.10.2
remote:        Installing chronic 0.10.2
remote:        Fetching numerizer 0.1.1
remote:        Installing numerizer 0.1.1
remote:        Fetching cinch 2.3.3
remote:        Installing cinch 2.3.3
remote:        Fetching concurrent-ruby 1.0.4
remote:        Installing concurrent-ruby 1.0.4
remote:        Fetching configatron 4.5.0
remote:        Installing configatron 4.5.0
remote:        Fetching daemons 1.2.4
remote:        Installing daemons 1.2.4
remote:        Fetching unf_ext 0.0.7.2
remote:        Installing unf_ext 0.0.7.2 with native extensions
remote:        Fetching eventmachine 1.2.2
remote:        Installing eventmachine 1.2.2 with native extensions
remote:        Fetching multipart-post 2.0.0
remote:        Installing multipart-post 2.0.0
remote:        Fetching websocket-extensions 0.1.2
remote:        Installing websocket-extensions 0.1.2
remote:        Fetching gli 2.15.0
remote:        Installing gli 2.15.0
remote:        Fetching hashie 3.5.1
remote:        Installing hashie 3.5.1
remote:        Fetching json 2.0.3
remote:        Installing json 2.0.3 with native extensions
remote:        Fetching mime-types-data 3.2016.0521
remote:        Installing mime-types-data 3.2016.0521
remote:        Fetching netrc 0.11.0
remote:        Installing netrc 0.11.0
remote:        Fetching method_decorators 0.9.6
remote:        Installing method_decorators 0.9.6
remote:        Fetching rack 1.6.5
remote:        Installing rack 1.6.5
remote:        Fetching tilt 2.0.6
remote:        Installing tilt 2.0.6
remote:        Fetching activesupport 4.0.13
remote:        Installing activesupport 4.0.13
remote:        Fetching chronic_duration 0.10.6
remote:        Installing chronic_duration 0.10.6
remote:        Fetching semantic_logger 3.4.1
remote:        Installing semantic_logger 3.4.1
remote:        Fetching mongo 2.4.1
remote:        Installing mongo 2.4.1
remote:        Fetching faraday 0.11.0
remote:        Installing faraday 0.11.0
remote:        Fetching websocket-driver 0.6.5
remote:        Installing websocket-driver 0.6.5 with native extensions
remote:        Fetching unf 0.1.4
remote:        Installing unf 0.1.4
remote:        Fetching mime-types 3.1
remote:        Installing mime-types 3.1
remote:        Fetching rack-protection 1.5.3
remote:        Installing rack-protection 1.5.3
remote:        Fetching faraday_middleware 0.11.0.1
remote:        Installing faraday_middleware 0.11.0.1
remote:        Fetching domain_name 0.5.20161129
remote:        Installing domain_name 0.5.20161129
remote:        Fetching sinatra 1.4.8
remote:        Installing sinatra 1.4.8
remote:        Fetching http-cookie 1.0.3
remote:        Installing http-cookie 1.0.3
remote:        Fetching rest-client 2.0.0
remote:        Installing rest-client 2.0.0
remote:        Fetching mailgun-ruby 1.1.2
remote:        Installing mailgun-ruby 1.1.2
remote:        Fetching faye-websocket 0.10.6
remote:        Fetching thin 1.7.0
remote:        Installing thin 1.7.0 with native extensions
remote:        Installing faye-websocket 0.10.6
remote:        Fetching slack-ruby-client 0.7.9
remote:        Installing slack-ruby-client 0.7.9
remote:        Using pagerbot 0.3.0 from source at `.`
remote:        Bundle complete! 9 Gemfile dependencies, 45 gems now installed.
remote:        Gems in the groups development and test were not installed.
remote:        Bundled gems are installed into ./vendor/bundle.
remote:        Bundle completed (32.88s)
remote:        Cleaning up the bundler cache.
remote: -----> Detecting rake tasks
remote:        Could not detect rake tasks
remote:        ensure you can run `$ bundle exec rake -P` against your app
remote:        and using the production group of your Gemfile.
remote:        /tmp/build_516621b0dcb6ff90cc1e17d94c4bc75e/vendor/ruby-2.5.3/lib/ruby/2.5.0/rubygems.rb:284:in `find_spec_for_exe': can't find gem rake (>= 0.a) with executable rake (Gem::GemNotFoundException)
remote:        	from /tmp/build_516621b0dcb6ff90cc1e17d94c4bc75e/vendor/ruby-2.5.3/lib/ruby/2.5.0/rubygems.rb:303:in `activate_bin_path'
remote:        	from /tmp/build_516621b0dcb6ff90cc1e17d94c4bc75e/vendor/ruby-2.5.3/bin/rake:29:in `<main>'
remote:
remote: ###### WARNING:
remote:
remote:        You have not declared a Ruby version in your Gemfile.
remote:        To set your Ruby version add this line to your Gemfile:
remote:        ruby '2.5.3'
remote:        # See https://devcenter.heroku.com/articles/ruby-versions for more information.
remote:
remote:
remote: -----> Discovering process types
remote:        Procfile declares types     -> bot, web
remote:        Default types for buildpack -> console, rake
remote:
remote: -----> Compressing...
remote:        Done: 21.3M
remote: -----> Launching...
remote:        Released v8
remote:        https://tranquil-stream-69081.herokuapp.com/ deployed to Heroku
remote:
remote: Verifying deploy... done.