Added .read() to extra_vars parameter as it is a File.
Merge pull request #14 from ansible/issue-14-unstable

Option for dynamic inventory group to sync respective sources
Merge pull request #10 from tee-jay/master

Added .read() to extra_vars parameter as it is a File.
Making extra_vars more flexible, adding tests.
Fix test failing on newer versions of click.
Merge branch 'master' into issue-15-unstable