Merge pull request #81 from coderhaoxin/master

correct the link
fix benchmarks for wrk(1) 3.x
update benchmarks in docs
update co for object yielding
docs
ugh travis is outdated
add koa Request / Response objects and delegation. Closes #52
Merge pull request #83 from koajs/add/ctx-request-response

Add/ctx request response
fix ctx.ip

need tests for this
Makefile: add test/application
response.etag and response.lastModified
Merge pull request #86 from koajs/etag-lastmodified

response.etag and response.lastModified
response.etag: remove getter for now

until we figure out a good way to return both weak and strong validators