Rewrite defunct 'have' matchers
Change "be_true" expectations to "be true"
Change "be_false" matcher syntax to "be false"
Require rspec ~> 3.0
Remove deprecated "treat_symbols_as_metadata_keys_with_true_values"

This was set to true, which is now the default with RSpec 3.
Explicitly allow both "should" and "expect" syntax