Fix default pin assignment within light providers.
Previous behavior was designed prior to having a config. library.
New behavior does not follow where the pin-property would be undefined. Undefined pin-values are now null.
Add tests to confirm new default pin behavior.
Merge pull request #16 from williambogaiv/update-default-light-pin-assignment

Update default light pin assignment
Add light config. for specifying what values represent off and on.
Currently implemented for raspi provider.
Merge pull request #18 from williambogaiv/add-raspi-off-on-config

Add light config. for specifying what values represent off and on
Add UI for displaying light-statuses.
UI is split into three-columns representing active TC-builds, Twitter feed, and TC pass/fail status.
Elements will scale based on viewport height and width (there may be some outliers where content breaks out of its container).
Updates to client are mostly done via socket-connection.
Add configurable Twitter queue value.
This controls the max. number of tweets visible.
Also add TeamCity and Twitter logos to panel headers.
And, fix issue where tweets were being added to the end of the queue instead of the front.
And yes, I probably should have renamed this to dequeue ;-).
Add ability to link to Twitter profile and status pages.
Update pass/fail panel so question-marks are displayed when toggling between states.
Also, update initial page-load logic so both states are visible as question-marks.
Merge pull request #20 from williambogaiv/add-ui

Add UI for displaying light-statuses