feat(store/store_bench_test.go) add a benchmark for set operation of store pkg
We randomly generage N 3 level keys. We benchmark the speed of setting each key into etcd store.
add a setWithJson test
add mem stats for sets benchmark
feat(store_bench) add set bench for different value sizes
add delete bench
feat(metrics): Add github.com/rcrowley/go-metrics
- Fix typo.
fix(store): TTL should range 1..n rather than 1..n+1

was experiencing intermittent functional test fails where TTL was eg 101
when 100 was expected
informal testing on a windows platform shows Go times resolving to the
nanosecond but with an accuracy of approximately 1 millisecond
I believe some of the functional test steps would run in under a
millisecond and cause the TTL to be recomputed with the same time.Now()
value resulting in a TTL that was +1 from the expected
Merge pull request #491 from jkakar/master

Trivial typo fix in API documentation
Merge pull request #480 from xiangli-cmu/store_bench

feat(store/store_bench_test.go) add a benchmark for set operation
Merge pull request #492 from rwindelz/fix-ttl

fix(store): TTL should range 1..n rather than 1..n+1
feat(metrics): Add metrics pkg
feat(metrics): Add documentation and contrib scripts
feat(metrics): enable some metrics; push to graphite

* -trace flag controls whether or not to enable metrics-gathering
  and the /debug/* HTTP endpoints
* -graphite-host flag controls where metrics should be sent
* timer.ae.handle metric tracks execution time of AppendEntriesRequest
test(store_bench_test.go) add watch bench
Merge pull request #493 from xiangli-cmu/bench_watcher

test(store_bench_test.go) add watch bench
bump(github.com/coreos/raft): bf7accb84ce4fe446983abffe00dd18a6b8cbc18
feat(metrics): Publish peer heartbeat events as metrics
test(ci): Replace travis.ci with drone.io
Merge pull request #496 from bcwaldon/droneio

test(ci): Replace travis.ci with drone.io