Bump version to 2.3.1

Add Carthage compatibility (#40)

* Swapped out the library target for a framework target

* Added YLTableView as a shared workspace scheme

* Updated podspec, renamed some stuff

* Updated deployment target

Merge pull request #33 from SirArkimedes/master

Fix Travis build

Merge pull request #34 from Yelp/fix-warning

Fix warning

Merge pull request #32 from Yelp/explicit_height_checks

Explicitly check for table header/footer height changes before forcing a relayout

Bump version to 2.1.2

Maintain the same YLTableView behavior on iOS11 (#30)

version 2.1.0

Merge pull request #19 from Yelp/basher_cocoadocs_cleanup

Documentation cleanup

Merge pull request #10 from Yelp/YLTableViewCellEstimatedRowHeight

YLTableView 2.0 - YLTableViewCell as protocol