Code server patch

[theramkm]

Allows Users to specify code server version. For eg ver 3.7.1 for some reason breaks python extension while 3.5.0 doesn't.

• updated requirements.txt to pyngrok>=5.0.0 so that pip install requirements work (it was 4.something before).
• updated version from 0.1.0 -> 0.1.1
• works in shell version and as an import in the main class.
• updated readme.

[abhishekkrthakur]

we dont need so many changes. If you want to do this, please make one variable CODE_SERVER_VERSION and point it to last stable release. In download use that variable. Only 2 lines of change. Thank you.