add support for golang

[luisdavim]

Something like this would colorise the output of grc go test -v ./..:

regexp==== RUN .*
colour=blue
-
regexp=--- PASS: .*
colour=green
-
regexp=^PASS$
colour=green
-
regexp=^(ok|\?) .*
colour=magenta
-
regexp=--- FAIL: .*
colour=red
-
regexp=[^\s]+\.go(:\d+)?
colour=cyan

[sir-farfan]

This configuration is working fine for me so far :)

[garabik]

fixed in 023c88b