__version__ breaks `pip`

[superbobry]

Unfortunately, __version__ trick in setup.py breaks bert installation:

Downloading/unpacking erlastic>=1.0.0 (from foobar)
  Downloading erlastic-1.0.0.tar.gz
  Running setup.py egg_info for package erlastic
Downloading/unpacking bert>=1.0.0 (from foobar)
  Downloading bert-1.0.0.tar.gz
  Running setup.py egg_info for package bert
    Traceback (most recent call last):
      File "<string>", line 14, in <module>
      File "/home/bobry/Code/env/build/bert/setup.py", line 5, in <module>
        from bert import __version__ as version
      File "bert/__init__.py", line 6, in <module>
        from bert.codec import BERTDecoder, BERTEncoder
      File "bert/codec.py", line 6, in <module>
        from erlastic import ErlangTermDecoder, ErlangTermEncoder, Atom
    ImportError: No module named erlastic
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 14, in <module>

  File "/home/bobry/Code/env/build/bert/setup.py", line 5, in <module>

    from bert import __version__ as version

  File "bert/__init__.py", line 6, in <module>

    from bert.codec import BERTDecoder, BERTEncoder

  File "bert/codec.py", line 6, in <module>

    from erlastic import ErlangTermDecoder, ErlangTermEncoder, Atom

ImportError: No module named erlastic