Expense Tracking

This release comes with a frequently asked feature, expense tracking. With this feature, a trip organizer can:

• Set a budget from the trip. This field is available in the Create Trip page as well as the Edit Trip form.
• View the currently set costs for transportation, lodgings or activities as expense records on the new tab.
• Add new expense records to capture more expenses and edit existing expenses as needed.
• View a breakdown of budget vs actual as well as percentage spending per category.

Full Changelog: v0.3.8...v0.4.0