Convert filenames with utf8 chars when outputting them in templates
    
    If a git repo has a filename in it with a utf8 encoded char,
    the template would previously fail to render with an error like:
    
        UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 1:
    ordinal not in range(128)
    
    This adds a filter to convert the utf8 charaters in the templates.
    
    The tests have also been updated to add a file to one of the repos
    with a non-ascii char.