0.8.3

• #223 - update default TLS version to 1.2 and support overriding via tls_options (thanks @duczen)
• #219 - fix py.test deprecated parameterization
• #217/#218 - python 3 fixes (mpub, AsyncConn)
• #214 - remove python 2.6 support
• #216 - update PyPI address in docs (thanks @aaronjheng)
• #212 - fix python 3.7 async keyword conflict
• #211/#213/#220/#225 - misc test/CI related fixes
• #210 - fix snappy/deflate high CPU load on disconnection (thanks @zexxonn)
• #208 - fix sending snappy/deflate compressed data (thanks @SpaTmole)
• #201 - specify tornado version in setup (thanks @jphines)
• #200 - update URL for NSQ protocol in docs (thanks @mecforlove)