Feature add flags scheduler

[rewiko]

Add the ability to setup a scheduler flags.

[kobolog]

Hey, thanks for the PR! Do you mind fixing the build? Looks like it happened because you changed the dependency management to glide and it pinned the Prometheus package to some more recent version that deprecated a part of the API.

[codecov-io]

Codecov Report

Merging #46 into master will increase coverage by 2.55%. The diff coverage is 65.11%.

@@            Coverage Diff             @@
##           master      #46      +/-   ##
==========================================
+ Coverage   30.83%   33.39%   +2.55%     
==========================================
  Files          18       18              
  Lines         762     1018     +256     
==========================================
+ Hits          235      340     +105     
- Misses        518      656     +138     
- Partials        9       22      +13

Impacted Files	Coverage Δ
core/options.go	15.15% <62.5%> (+15.15%)	:arrow_up:
core/context.go	11.86% <65.38%> (+6.47%)	:arrow_up:
util/map.go	64.7% <66.66%> (-35.3%)	:arrow_down:
util/net.go	85.71% <0%> (-1.79%)	:arrow_down:
core/store.go	3.04% <0%> (-0.61%)	:arrow_down:
pulse/tcp.go	100% <0%> (ø)	:arrow_up:
util/time.go	100% <0%> (ø)	:arrow_up:
pulse/options.go	100% <0%> (ø)	:arrow_up:
pulse/metrics.go	100% <0%> (ø)	:arrow_up:
core/runtime.go	0% <0%> (ø)	:arrow_up:
... and 8 more

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[sebbonnet]

@kobolog we've added a few more tests and fixed the build by ensuring we install the dependencies via glide. Travis builds on both golang 1.8 and 1.9 as tip didn't work for glide.

[kobolog]

Great, thank you for your work!