YTranslator interface was chainged:
  init_key_from_path method removed, Translator get api key from __init__ arguments only.
  If we pass str to YTranslator.translate method, method returns string,
  if we pass other iterable object, method returns list.
+ some tests.
Merge pull request #5 from odeke-em/master

Enhanced README.md; Shebang for ytranslate.py
fix travis script