Adds new context caching system

- Reduces allocation overhead
- Reduces Garbage Collection stress
- Reduces memory fragmentation
Added Google App Engine Example
Added README.md
Fix

Modified ping path and added a comment explaining why init() is called
like that.
Clarification
Merge pull request #26 from javierprovecho/master

Added Google App Engine Example
Run() crashes if server can't be setup
Merge branch 'develop'
Adds NewWithConfig() and CacheStress()
Adds Keep() and Release() to gin.Context
Added support for OPTIONS verb
Added OPTIONS to README
Testing Copy() instead of Keep() and Release()
Improves Copy() in gin.Context
Merge branch 'contextCaching' into develop
Merge branch 'options' of https://github.com/alexandernyquist/gin into alexandernyquist-options
Adds HEAD
base travis ci config
including build status in readme
removing CI for go v1.0