Exporters

- Bugfix on S3Reader: it was skipping every other key
- Updates to documentation, added examples dir
- Mark item as finished in HS reduce writer

New Features:
- Azure blob writer
- Azure file writer
- Date rages support for filebases
- Improved logging
- Added metadata object to modules
- Optional consistency checks for all file based writers
- Exported file name is now the same as compressed file name
- Moved from nose to py test environment
- Adds integration tests
- Adds flake8 checks
- S3 to azure blobs bypass
- S3 to azure files bypass
- Possibility of disabling retries

Bug fixes:
- Fix retries for mail notifications module
- Fix tests leaving dirty tmp folder
- Tons and tons of small fixes

- Fix MailWriter to support loading keys from environment

New Features:
- Dropbox writer

New Features:
- Adds md5 consistency checks support for s3 writer
- Improves debugging features for reduce writer
- Adds header option for xml exported files
- Adds md5 checksum generation in file based writers

Bug fixes:
- Fixes permissions bug in s3 to s3 bypass