ci: add staticcheck to linting

See #6

.gitlab-ci.yml

@@ -27,9 +27,11 @@ gofmt linting:
   allow_failure: true
   <<: *only-default
   before_script:
-    - apk -q add go
+    # specific mirror used because staticcheck hasn't made it to the other mirrors yet...
+    - apk -q update --repository http://dl-4.alpinelinux.org/alpine/edge/testing
+    - apk -q add --repository http://dl-4.alpinelinux.org/alpine/edge/testing go staticcheck
   script:
-    - .gitlab-ci/check_gofmt.sh
+    - .gitlab-ci/check_linting.sh
 
 build:
   stage: build

.gitlab-ci/check_gofmt.sh

@@ -1,11 +0,0 @@
-#!/bin/sh
-
-files="$(gofmt -l .)"
-
-[ -z "$files" ] && exit 0
-
-# run gofmt to print out the diff of what needs to be changed
-
-gofmt -d -e .
-
-exit 1

.gitlab-ci/check_linting.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+echo "### Running gofmt..."
+files="$(gofmt -l .)"
+
+if [ !  -z "$files" ]; then
+	# run gofmt to print out the diff of what needs to be changed
+	gofmt -d -e .
+	exit 1
+fi
+
+echo "### Running staticcheck..."
+staticcheck ./...