rough version of clickable budget summary tab
handled edit/delete Budget
Added edit budget tests and add budget with api calls.
switches to BudgetSummaryActivity when clicking on a Budget; Changed some minor details in BudgetSummaryActivity for consistency
made it switch themes dynamically
Fixed some redundancy and improper assert uasge
Modified a string to preemptively fix a bug that will surface after #125 merges
Fixed more redundancies.
Merge pull request #124 from coldstar96/edit-budget-tests

Edit Budget tests and API-included Add Budget Tests
Merge pull request #125 from coldstar96/edit-delete-budget

Edit delete budget
Changed a budgetId to a BudgetId
Solved merge conflict with Ji's branch