Tradução do Blog post 2017 04 07 react v15.5.0.md (#209)

* translated intro from React v15.5.0

* translated "new deprecation warning" from React v15.5.0

* translated "migrating from reactproptypes" from React v15.5.0

* translated "migrating from reactcreateclass" and "discontinuing support for react addons" from React v15.5.0

* translated "installation" from React v15.5.0

* translated "changelog" from React v15.5.0

* fixed typos and improved semantic on v15.5.0 blog post translation