Adding service for obtaining reference to google visualization api

- Defines "get" method which uses googles "setOnLoadCallback" method as a callback to run when Google Visualization API is loaded
Merge pull request #25 from stulees/feature/visualization-service

Adding service for obtaining reference to google visualization api
Revising visualization service to use unique module name and add file to build

- svc-visualization-api updated with single quotes to appease jshint and also adding visualization to the module name
- ran gulp build and now included in built file
Merge pull request #26 from stulees/master

Revising visualization service to use unique module name and add file to build