Return bash variable declaration as name-value pair.

    Name as lower case str. Value itself only without surrounding '"' (if any).

    For example, _line_2_pair('NAME="Ubuntu"') will return ('name', 'Ubuntu')

def _line_2_pair(line):
    '''Return bash variable declaration as name-value pair.

    Name as lower case str. Value itself only without surrounding '"' (if any).

    For example, _line_2_pair('NAME="Ubuntu"') will return ('name', 'Ubuntu')
    '''
    key, val = line.split('=')
    return key.lower(), val.strip('"')