Optionally build repo on push event

[ElvishJerricco]

Have a configuration setting to allow building the repo on the push event and setting the commit status. This is useful for those of us who fly by the seat of our pants and push directly to master =P

This is the model of nix-simple-ci, but I'd rather consolidate these two projects than have two different projects, each with fewer features. Does that sound like a good idea to you? I'd be happy to open a PR to merge these and close this issue.

[ocharles]

Certainly open to having this. If people don't want it, they simply don't enable the push event, right?