Merge tag '2.0.4' into develop

Bug fix to handle HTTP 202 response codes
ManagedSources
Solved issue on require managed_source
User agent reenabled
Correct createManagedSource
Correct createManagedSource
Some comments on code
Remove Hi there,
Merge remote-tracking branch 'giovannelli/master' into feature/managed-sources-beta
Modified pull request 38 adding managed Sources support
Include JSON gem in gemspec
Removed requirement for specific managed source types
Merge pull request #39 from datasift/feature/managed-sources-beta

Feature/managed sources beta
Bumped to v.2.1.0.beta
Merge branch 'release/2.1.0.beta'