Update to Python 3.7 + all dependencies

• Update to use Python 3.7 + latest Python dependencies in Docker image
• Handle lost websocket connections to Chrome tabs

Minor update

• Update to the latest devtools protocol from Github as of 20 Jan 2018
• For trigger events, only build the resulting chromewhip hash from the hashable fields in the actual payload.
• Tested locally on Mac OS, Chrome Canary 66.0.3326.0 (Official Build) canary (64-bit), Python 3.6.3

v0.2.1-alpha

• Remove workaround for "go" implementation as chromium bug 747224 fixed on Canary (tested on Chrome Google Canary v62.0.3181.0)

v0.2.0-alpha

• Extended low-level asyncio driver to allow for input events for id source
• Page.navigate is now more reliable

First alpha release

• HTTP server that supports HTML and PNG rendering
• first iteration of the asyncio driver API that supports the devtools protocol as of chromium r488555
• HTTP server can be deployed easily as a standalone Docker container