[COOK-2297] more gracefully handle pip packages from VCS or source archives
Merge pull request #28 from Frick/master

[COOK-2297] more gracefully handle pip packages from VCS and source archives
also look for https
release v1.2.2
Support installation of packages version other than the default on 'debian' family.
Improved handling for specifying Python versions.
Explicit precedence when setting attributes (implicit precedence is deprecated).