Adding Contains and doesNotContains operator
Adding tests for both contains and doesNotContains
Updating docs with contains example
Adding support substring to contains feature

- i.e. if strpos($a, $b) !== FALSE
Refactoring doesNotContain to use the negation of contains.
Lowercasing falses and adding newline before return statement
Removing the doesNotContain method

Instead we rely on the negation of the "contains" method
Lowercasing SHOUTY types
Merge pull request #11 from malaney/contains_feature

contains and doesNotContain comparison operators