Update connection.py

Included sms info for subscribe.
Merge pull request #1744 from innovatifi/patch-1

Update connection.py
fix UnboundLocalError when trying to remove rule from empty security group
self.rules is of type IPPermissionsList, remove method takes no kwargs
Test changes to allow overriding has_google_credentials.
Merge pull request #1752 from reinhillmann/develop

Test changes to allow overriding has_google_credentials.
Nicer error messages for 403s for object and ACL access.
Merge pull request #1753 from zwilt/develop

Nicer error messages for 403s for object and ACL access.
Adding epub output format, even though it requires a newer version of Sphinx.

Main motivation is people might want to read the documentation for the definitive Amazon AWS interface library, being Boto, on an Amazon Kindle. ePub is easily converted to any other ebook format, such as .mobi for Kindle.
Merge pull request #1759 from geekpete/develop

Adding epub output format, even though it requires a newer version of Sp...