서승완 / kappa

If "kappa delete" fails midway then re-running it will fail during
role removal.

This PR modifies `delete` to check if the role exists.  If it does not
then we log a debug line and return early.

I also consolidated various methods that were calling `get_role` so that
error handling is consistent, and removed `_find_all_roles` as
`get_role` is sufficient, and probably faster (particularly for accounts
with many roles).

Event source refactor

Packaging Improvements

Also cleanup travis installation

- Read requirements from requirements.txt
- Support both setuptools and distutils
- Use wrapper for opening the correct file for requirements.txt and the readme
- Import version from package
- Hardcode package list
- Avoid reading in entire license file when specifying the license attribute

Show errors and stop function.create when ClientError

Fix vpc_config parameters

typo in Quick Start

Add vpc_config to md5

Fix retrieval of resources when user is using statements

Add ability to enable and disable S3EventSource

Fix disabling event sources

typo in "event_sources disable" cli-command