Fix missing parentheses on declaration of infix operators
Preserve -> in sequence expression

After do, expressions should go to a new line
Merge pull request #11 from forki/master

And I keep spamming failing tests.
Merge branch 'master' of https://github.com/dungpa/fantomas
Fix missing optional arguments in function calls

99 tests passed/8 tests failed
Introducing a test helper in order to make the tests shorter