Autoupdate a coverage badge in your README.md with this one dumb trick!
To try it out:
go get github.com/natefinch/covergen
Then run go test:
Now run git diff... the url for the coverage badge in README.md is updated automagically! No other commands need be run.
Check out covergen_test.go for how it works.
The only drawback is that you more than double the time it takes to run your tests...