Require rspec ~> 2.99

Tests break in newer versions of RSpec due to deprecated usage.
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.
Change "should" syntax to "expect" style

This just changes the "shoulds" that raise deprecation warnings.
Merge pull request #5 from L2G/rspec-2-deprecation

Update to RSpec 3 syntax