Added performance graph

Signed-off-by: Vishal Rana <vr@labstack.com>

Separated Group from Echo to limit API

Signed-off-by: Vishal Rana <vr@labstack.com>

Encapsulated fields and exposed public functions.

Signed-off-by: Vishal Rana <vr@labstack.com>

Merge pull request labstack#76 from labstack/websocket

New definition for Echo.HandlerFunc

Merge pull request labstack#70 from labstack/websocket

Wrapped Flush, Hijack and CloseNotify functions in response.

Updated docs

Signed-off-by: Vishal Rana <vr@labstack.com>

Merge pull request labstack#40 from labstack/develop

Nested groups

Fixed a typo

Signed-off-by: Vishal Rana <vr@labstack.com>

Update README.md

Merge branch 'master' of https://github.com/labstack/echo