Merge pull request #12 from lofiinterstate/feature/sorting

- Adding sorting and default sort functionality. 
- Added ReactableTestUtils to reset the environment and expect a row to have certain text to aid in testing this.
Version 0.2.0

Added sorting and changed pagination API
Simplify after() callbacks in tests

In the interest of making code more concise, make
ReactableTestUtils.resetTestEnvironment get passed directly to after();
everywhere rather than making an anonymous function that calls it.
Merge pull request #16 from lofiinterstate/feature/sorting

Adding numeric sort function
Adding Currency and Date sort functions

Working on #14