Error importing bmipy-render output on Windows

[mdpiper]

On Windows, an error is thrown when attempting to import from a file created by bmipy-render. To reproduce it, try these steps:

1. Clone the bmi-python repo and install bmipy from source.
2. From the command line (I used the Git Bash shell), use bmipy-render to create a new file for a MyBmi class:

$ bmipy-render MyBmi > mybmi.py

1. Try to import the class from the module:

$ python -c "from mybmi import MyBmi"

The result is an error, with message

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\Mark\projects\bmi-python\mybmi.py", line 539
    """
       ^
SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0x93 in position 483: invalid start byte

[mdpiper]

The same error occurs using the conda-forge bmipy package.

[mdpiper]

Be sure to revert 5c9bc76 when this issue is fixed.

[mcflugen]

Fixed with #45.