gnsrulescheker -> gns-cli

 - Make gnsruleschecker as a part of gns-cli.
 - Some other refactoring things
```python
class VCR(object):
    def __init__(self,
                 serializer='yaml',
                 cassette_library_dir=None,
                 record_mode="once",
                 filter_headers=[],
                 filter_query_parameters=[],
                 before_record=None,
                 match_on=[
                     'method',
                     'scheme',
                     'host',
                     'port',
                     'path',
                     'query',
                 ],
                 ignore_hosts=[],
                 ignore_localhost=False,
                 ):
```