Doesn't work in python 3.7

[himanshu219]

I am getting following error when trying to run in MacOS with python 3.7

Traceback (most recent call last):
  File "/Users/hpal/.pyenv/versions/awstest3.7/bin/changes", line 11, in <module>
    sys.exit(main())
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/click/core.py", line 610, in __call__
    return self.main(*args, **kwargs)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/click/core.py", line 590, in main
    rv = self.invoke(ctx)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/click/core.py", line 933, in invoke
    Command.invoke(self, ctx)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/click/core.py", line 782, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/click/core.py", line 416, in invoke
    return callback(*args, **kwargs)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/changes/cli.py", line 44, in main
    no_input, major, minor, patch,
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/changes/version.py", line 25, in get_new_version
    patch=patch
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/changes/version.py", line 48, in increment
    version = semantic_version.Version(version)
  File "/Users/hpal/.pyenv/versions/3.7.0/envs/awstest3.7/lib/python3.7/site-packages/semantic_version/base.py", line 102, in __init__
    raise ValueError("Call either Version('1.2.3') or Version(major=1, ...).")
ValueError: Call either Version('1.2.3') or Version(major=1, ...).