Move shared examples into their own directory.
Add support for calculating a literal's path.
Fix Ruby driver to be able to identify correct source locations for statements that appear more than once in a single program.
Ensure that replacements are merged into program source in the order in which they appear.
Extract replacement, substitution and matching as separate concerns using the visitor pattern.
Add Rails where(...).first -> find_by(...) example.
Make parser and unparser runtime dependencies.
Make room for integration tests.
Extract first set of integration tests.
Add integration tests for Metamorpher::Refactorer and refactor the implementation a little.
Update README to discuss blocks supported by Rewriter#reduce and #apply.
Ensure that Metamorpher::Refactorer is required by default.
Fix #1. Delete old test cases, now that integration tests have been extracted.
Added documentation on Refactorer#refactor_file and #refactor_files to README.