Setup CI
Fix date_ext_tests

1.9.3 implements Date.today in C so mocking the returnvalue of Time.now does nothing

Ref: 1408b942d9c2c131a1cdcab97f49d74ce84dae38
Github: https://github.com/rails/rails/commit/1408b942d9c2c131a1cdcab97f49d74ce84dae38
Bump up tzinfo (1.9.3 compat)
Fix invalid yaml
Backport OrderedHash from rails/master
bump mocha dependency
Bump up mocha