Initial segment.io integration

Added Segment.io configuration and initial 'page' call, the 'identify' call to track users, and 'track' calls for the following events:

- Search
- Workspace Created
- Workspace Creation Error
- Data Source Created
- Data Source Creation Error
- Sandbox Added
- Workspace Members Updated
- Workspace Settings Edited
- Workspace Settings Error
- WorkFile Uploaded
- Job Created
- Work Flow Task Created
- Milestone Created
- Note Created
- Insight Created