Bytecode compilation issue in Python 2.7.x

[yegorich]

python -m compileall . produces following error in ./serial/aio.py:

Compiling ./serial/aio.py ...
  File "./serial/aio.py", line 366
    def open_serial_connection(*,
                                ^
SyntaxError: invalid syntax

Python 3.x compiles without error.

[zsquareplusc]

Yes, that's Python 3 syntax. The module does not work with Python 2 anyway. But I can look if there is a workaround.

[zsquareplusc]

Well if that is fixed, the next issue will be yield from...

[yegorich]

Can you exclude aio.py from installation, when using Python 2?

[rob-smallshire]

I've submitted #131 which modifies the install script to not install aio when running on Python 2. This will allow us to continue to use Python 3 syntax in the aio module, which will only ever work on Python 3.4+ anyway.