Threatconnect

+ Added missing pytz module dependency.
+ Updated test cases

+ added index support to Resource
+ added options=createVictim to Email resource commit

+ Fixes in setup.py for Python 2.6
+ Fixed issue for custom indcator IndexError

+ Added Campaign support.
+ Added delete file occurrence functionality.

- Fixed issue with proxy when accessing IndicatorType.
- Added id to File Occurrence.
- Updated **string** structure for File Occurrence.
- Updated **string** structure for Task.
- Removed redundant set_description() call on IndicatorObjectAdvanced.
- Updated EmailAddress regex.
- Updated Attribute Object to handle attribute with no value.
- Merged pull request with new Host regex.

- Update for Null Indicator value in Resource Object