Vcoclient

Added:
- Installation support now via pip3 install vcoclient
Changed:
- Documentation in vcoclient.py, README and Changelog

Changed:
- There is now a ``msp_customers_get``and a ``operator_cusgtomers_get`` to support operator or partner customers respectively. Thereby ``customers_get``has been removed
- Better error handling for exceptions in execusion class.
- Printing only out something if there is anything to print out after execusion has happened.
- Handling invalid user/password and missing cookie better

Changed:
- Merged functions into one Class for easier creating new methods for vcoclient. Rather then having a function for each argparse, we have one Class taking care of it.
Removed:
- Fixed warning issue with Pandas renaming syntax of index
- Removed memory footprint of variables

Added:
- Using getpass for ``--password`` to make it more secure.
- Adding os.env option for username (VCO_USER), password (VCO_PASS) and host (VCO_HOST) for easiness.
- Adding functionality to get row names only via ``--rows_name`` from results.
Change:
- Handling hostname has changed and will raise exception if not given via os or input by user.
- Handling data structure more efficiently (e.g. unpacking only needed value from list)

Added:
- ``--search`` in edges_get for searching any value related to edges properties. Gives one a powerful method to extract/compare values between many edges.
Changed:
- Method login and logout will not return True anymore but will just execute as is and will raise an exception otherwise.

Added:
- Output of Pandas, JSON or CSV, will have the name of the Edge rather as a returned index. Simpler to read.
- ``--filters`` lets user to filter output more granular
- User can now define another enterprise ID rather then the default 1
Changed:
- ``--search`` changed to ``--name``in edges_get, reflecting really what is filtered