Enable hacking check for Apache 2.0 license

Removes H102 (license header not found) check from flake8
ignore list.

Adds missing apache license headers.

Change-Id: I109f23c6d8b2e3efb1dac7f764bd77e0d9d335f0
Fix incorrect help message on flavor_access action

The help message of params "flavor" and "tenant" is incorrect on
do_flavor_access_add and do_flavor_access_remove.

Change-Id: I66c45316181307305a19aec25acefc019cd7bdfc
Closes-Bug: #1258453
Merge "Enable hacking check for Apache 2.0 license"