Rename ambiguous test name to what it actually tests
- Stop passing redundant `:engine => Table.engine` to `Table#new`
- Remove redundant `ast` variable creation
- Rename similar join tests name to what they actually test
- Move "joins itself" test to "joins" describe instead of defining describe block twice
- Move update manager statement tests in logical order
- Move `project` tests in logical order
Merge pull request #291 from vipulnsward/rename-test

Cleanup SelectManager Test