Install of Mazer fails outside a terminal without LANG=C.UTF-8

Bug Report

MAZER VERSION

Recent devel branch. Cannot run mazer because it fails on install of mazer.

CONFIGURATION

No configuration present, all defaults.

SUMMARY

Install of Mazer fails outside a terminal without LANG=C.UTF-8

STEPS TO REPRODUCE

Try to install mazer in any environment which isn't a user terminal and may not have locale set to UTF-8, because this changes the default encoding which setup.py tries to open README.rst and fails on non-ASCII characters.

unset LANG
pip install mazer

EXPECTED RESULTS

Mazer should install itself.

ACTUAL RESULTS

Mazer fails to install, dying when pip executes the setup.py script.

    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-tudein1l/mazer/setup.py", line 9, in <module>
        readme = readme_file.read()
      File "/usr/lib/python3.6/encodings/ascii.py", line 26, in decode
        return codecs.ascii_decode(input, self.errors)[0]
    UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 2665: ordinal not in range(128)

ansible / mazer