Implement DB URL connection support

[gabor-boros]

Reason for the change
This PR is related to rethinkdb/rethinkdb#4101.

Description
Add DB connection URL support.

Code examples

>>> from rethinkdb import r
>>> url = "rethinkdb://admin@127.0.0.1:28015/test?timeout=30"
>>> conn = r.connect(url=url)
>>> r.table_create('marvel').run(conn)
{'config_changes': [{'new_val': {'db': 'test', 'durability': 'hard', 'id': '57d565e9-55ca-42f8-85e6-792068ad4a52', 'indexes': [], 'name': 'mar
vel', 'primary_key': 'id', 'shards': [{'nonvoting_replicas': [], 'primary_replica': 'gabor_local_umw', 'replicas': ['gabor_local_umw']}], 'wri
te_acks': 'majority', 'write_hook': None}, 'old_val': None}], 'tables_created': 1}

Checklist

• Unit tests created/modified
• Integration tests created/modified

References

[gabor-boros]

Here is an overview of what got changed by this pull request:

Coverage increased per file
===========================
+ rethinkdb/net.py  1
         

See the complete overview on Codacy