Add some vetting to travis

Signed-off-by: Jguer <me@jguer.space>

.travis.yml

@@ -1,18 +1,20 @@
 sudo: required
 notifications:
-    email: false
+  email: false
 language: generic
 services:
-- docker
+  - docker
 
 arch:
   packages:
-  - git
-  - go
+    - git
+    - go
   script:
-  - make
-  - make test
-  - ./testdata/install_test.sh
+    - go tool vet .
+    - diff -u <(echo -n) <(gofmt -d ./)
+    - make
+    - make test
+    - ./testdata/install_test.sh
 
 script:
-- "curl -s https://raw.githubusercontent.com/mikkeloscar/arch-travis/master/arch-travis.sh | bash"
+  - "curl -s https://raw.githubusercontent.com/mikkeloscar/arch-travis/master/arch-travis.sh | bash"