Revert "Revert "Run Fog tests for Ruby 2.2.0""

This reverts commit 35fea348878a329ee10e65a6b7edd37d97301e73.
get_topic_attributes handle nil values

* also correctly rstrip request id
[aws/sns] basic subscription mock
Merge pull request #3373 from engineyard/sns-subscriptions-mock

[aws/sns] basic subscription mock
Merge pull request #3372 from engineyard/get-topic-attributes-fix

[aws] get_topic_attributes handle nil values