travis: Also run Go tests where they exist, when running through Travis

.travis.yml

@@ -2,4 +2,6 @@ language: go
 
 install: make deps
 
-script: make
+script:
+- make
+- make test

Makefile

@@ -49,3 +49,6 @@ arm6:
 
 deps:
 	go get -v -d
+
+test:
+	cd irc && go test .