Create script to update skeleton in nexB project repos

[JonoYang]

Currently, if we wanted to update the skeleton files of a nexB project, we would have to go into every project to:

• Add the skeleton as a new origin
• Create a new branch where we merge in skeleton files
• Handle merge conflicts
• Push the new branch to github
• Merge in the new branch

It would be nice to have a script to automate some portion of this process. The script can handle:

• Cloning a repo
• Adding the skeleton as a new origin for that repo
• Creating new branch and merging in the skeleton files

Then the user would handle merge conflicts and then push the branch to github. Afterwards, the script moves onto the next repo.