Work in progress resolution of a test order dependence fix.

By adding minitest_bisect to the Gemfile and bundling, we can determine the test causing contamination.

In this case, test_default_values_in_superclass_are_saved_in_subclass|test_can_specify_default_value_via_association.

Fix test_default_values_in_superclass_are_saved_in_subclass, by changing the subclass from TestClass to TestClass2 to avoid polluting TestClass with an ancestor TestSuperclass which has a default_value for number.
Revert "Make tests order-dependent for now."

This reverts commit 4d532f323dee5bd8b2ae63f3cc07b1864199b1bc.
Merge pull request #48 from jrafanie/fix_order_dependent_tests

Fix order dependent tests