Fix for TimberPost Aliasing Error

Added a call to Timber\Timber constructor when Timber is installed via Composer. This will properly alias Timber\Post and prevent a fatal error.

Gulp build processes

• Replaced the no longer supported Compass in favor of Gulp for front-end build tasks.
• Added a Gulp task to automate releasing the plugin to the WP plugin repository.

Adding filter to 'Add Posts' search box

• Addresses #56 - The Add Post' search metabox will now use the same filters applied to the stream when querying posts.
• Updated Travis config to test against newer versions of php and WordPress.

Fix for TimberStream constructor error

Addresses #52

• Added a conditional to check whether TimberStreams are the correct post type rather than throwing an exception. The will prevent the subclass check performed in Timber::PostGetter from throwing an error and preventing posts from being saved.
• Moved constructor logic into init_stream function, following the pattern used in the Timber classes.

1.2.1

Tweaked readme text, replaced placeholder text in Help tab with instructions.

Initial release

1.2

Removed unused sm_rules box code

Added Scheduled Posts Feature

• Stream Manger now will recognize and inject scheduled posts
• Mike B's Travis fix is included