updated git package to not depend on python

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
Merge remote-tracking branch 'origin/pr/390' into develop
Revert "switch to using go-agent lucid stemcell for aws"

This reverts commit f1bb63de6ad87bdf5aa6608f0242d4b709b01c0e.