Begin support for Ruby 2.1.2 .
Merge remote-tracking branch 'Lewis-Clayton/master'
Extend Listener::GoogDrv#get_unseen_files to detect changes.

Previously, `Listener::GoogDrv#get_unseen_files` detected new files.
Extend to read `updated`, with `etag` if present, and use these as a
checksum. This is similar to `Listener::FTP#get_unseen_files`.

Note that this might cause notifications to be made even if the content
has not changed, but if that is important, it is expected that it will
be handled and filtered worker-side.
Fix typo bin/ryespy --goog-drv-filters P1 => F1 .
Fix missing Listener::Base requires.
Test Listener::GoogDrv .
Update README,gemspec in a major way.
Bump version to v1.1.0, updating CHANGELOG.
Merge branch 'release/v1.1.0' into stable
goog_drv - 1000 changes per request