'Look for any environment variables that start with \'AC_\'. Returns dict of key:value pairs, where the
key is the result of removing \'AC_\' from the variable name and converting the remainder to lowercase.
For example, \'AC_DEBUG=1\' becomes \'debug: 1\'.
:return ruamel.yaml.compat.ordereddict'

@staticmethod
def _get_environment_variables():

    logger.debug(u'Getting    environment    variables...')
    env_vars = yaml.compat.ordereddict()
    for (var, value) in ((k, v) for (k, v) in os.environ.items() if k.startswith('AC_')):
        env_vars[var[3:].lower()] = value
    logger.debug(u'Read    environment    variables', env_vars=env_vars)
    return env_vars
