Merge pull request #105 from tiger-swallowtails-2014/skip_speed_test

Add functionality to skip speed test if WPM has already been calculated.
model tests for book and parapgraph
user model tests
book and paragraph model tests
Merge pull request #106 from tiger-swallowtails-2014/kh_controller_tests

Kh model tests
Hide skip button on speed_test start