Merge pull request #25 from natgeo/develop

Update master with develop
Merge pull request #29 from natgeo/develop

Update master with develop
Merge branch 'master' of github.com:natgeo/modules-activitystream
Merge branch 'develop' of github.com:natgeo/modules-activitystream
[MIE-1530] - Updating gemfile
[MIE-1530] - Making expandable activity items. New hover state functionallity.
[MIE-1530] - Make item expandable for longest users names.
[MIE-1530] - Set height auto on activityitems for mobile.
[MIE-1530] - Fix bad alignment for iPads and related mobiles.
[MIE-1530] - PR applying code convention coffee style.
[MIE-1530] - PR. Flattening css structure.
Merge pull request #31 from natgeo/feature/MIE-1530

Activity items have different height sizes.