Add metric metadata endpoints#181

Merged

yannmh merged 10 commits intomasterfrom

agrant/metrics_metadata

Jan 20, 2017

Commits on Jan 4, 2017

1st pass at adding metric metadata operations to api
flapjack103
committed

Commits on Jan 12, 2017

[flake8] fix violations
Yann MAHE
committed

Commits on Jan 17, 2017

changing how update request is called; updating docstring on update method
flapjack103
committed
Merge branch 'agrant/metrics_metadata' of github.com:DataDog/datadogpy into agrant/metrics_metadata
flapjack103
committed

Commits on Jan 20, 2017

removing CreateableAPIResource and ActionAPIResource
flapjack103
committed