use auth_handler to specify host header value if possible
a more robust test for the function
Delete the changelog.

Since it hasn't been updated in 2 years.
Merge pull request #1870 from Celc/patch-1

Delete the old changelog in favor of the README link to ReadTheDocs changelogs. Fixes #1870.
Merge pull request #1872 from juanfont/develop

Add support for RDS CopyDBSnapshot. Fixes #1872, #1865.
Remove changelog from manifest.
Add max results parameters to EC2 describe instances and describe tags calls. Also updates describe spot instance price history call with a max results parameter.
Merge pull request #1873 from danielgtaylor/ec2-max-results

Add max results parameters to EC2 describe instances and describe tags. Fixes #1873.
Version bump to 2.19.0 and added release notes.
Merge branch 'release-2.19.0' into develop.
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
Merge pull request #1883 from henrysher/henrysher-patch-boto-utils

Add a retry when EC2 metadata is returned as corrupt JSON. Fixes #1883, #1868.
Try to use unittest2 for Python <=2.6 when testing utils - fixes an exception on older Pythons when asserting that an exception is thrown.