Python 3.7 support (fix deprecated yaml call)

[oscarlofwenhamn]

When starting kube-shell i get the following warnings:

c:\python37\lib\site-packages\kubernetes\config\kube_config.py:280: YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
  config_dict=yaml.load(f),
c:\python37\lib\site-packages\kubeshell\kubeshell.py:43: YAMLLoadWarning: calling yaml.load_all() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
  for doc in docs:

Since they reference YAMLLoadWarning: calling yaml.load_all() without Loader being deprecated I am guessing this is a question of updating to new 3.7 standards.

However, I am noticing the last commit was sept 19 2018, so I understand if this is a dead project.

[Langvann]

Add the following to kubeshell.py and kube_config.py to suppress warnings:
yaml.warnings({'YAMLLoadWarning': False})

[oscarlofwenhamn]

Thanks for the tip!

[oscarlofwenhamn]

However, is this something that can be done after installing the script or does it require cloning and rebuildning? Would it be worth adding to the source repo?