payloads/http: adding generic util function for routes
build route: for statuses
adapters/build: base functions, linked via default_events
vcs & vcs/github: filter out PRs that already have statuses
adapter: catch errors for plugins
proposal & pr fixtures: update user data
vcs/github: update generateVcsPayload to always return a promise, update tests
vcs/github: remove extra catch
Merge pull request #53 from chr0n1x/overhaul

Filter out Github PRs that have statuses, catch() in executeInPlugins()