This pull request splits general test and export structuring refactoring from #335 and #348 . Previously parser tests weren't being run because they were defined in a nested directory. Upon including those tests, errors began to occur due to circular dependencies in Webpack (see webpack/webpack#1788). The changes here resolve this by moving the registration behaviors into its own file so the dependency between the parser and registration is more direct. In doing so, the blocks folder was flattened to bring parser to the top-level directory.