Detects Microsoft WSL kernel and installs python3-dev

[sirredbeard]

Closes#107, provides python3-dev needed for building netifaces extension. Tested by hand on Ubuntu on WSL.

[sarun87]

Wonder if there is a specific field we can look at rather than a blanked grep. It does fix the issue quickly, so lgtm.
/lgtm
/approve

[sirredbeard]

There really isn't a great way to detect if you are running inside WSL other than to check for microsoft in the WSL1 "kernel" or WSL2 kernel uname string. The next best alternative is attempting to run a Windows .exe as a test, something like cmd.exe /C "echo" and checking the exit code.

See the extensive discussion here microsoft/WSL#423