use auth_handler to specify host header value if possible
a more robust test for the function
Add support for Amazon Kinesis
Add a license and handle timeouts if the stream never becomes active or no records are ever read within the given time limits.
Explicitly call time.sleep to make grepping easier
Added more DBSnapshot attributes
Merge branch 'release-2.19.0' into develop.
Updating elasticache parameters to be optional

With the addition of Elasticache for Redis, AWS has made certain
parameters to the endpoint optional. This commit reflects that change.
Added new params to DBSnapshot unit tests
Added some missing attributes to DBInstance
documentation of launch config in Autoscaling Group was wrong

The documentation mentioned a parameter called launch_config_name, but it's really called launch_config.
typo: AIM -> IAM
Merge pull request #1882 from alexjurkiewicz/develop

typo: AIM -> IAM
add a retry when metadata fetched with a corrupt JSON format
Fixes #1868
re-factored patch to make it more testable, added unit test
Merge pull request #1880 from juanfont/develop

Added some missing attributes to DBInstance and DBSnapshot. Fixes #1880.
Merge pull request #1881 from luisbarrueco/develop

Fix documentation of launch config in Autoscaling Group. Fixes #1881.
PEP8 Issues
Fixed bug when arg==0 (issue #1886)
Changed backup_retention_period type to int (as in AWS doc). Tests updated.