[epiphany] CI: Add cppcheck check

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 9a479479933c91fded146426c2efbb5853a96fff
Author: Jan-Michael Brummer <jan brummer tabos org>
Date:   Tue Jul 16 20:53:16 2019 +0200

    CI: Add cppcheck check

 .gitlab-ci.yml | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 07798b2e5..f64121576 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -13,6 +13,15 @@ check-code-style:
   script:
     - bash data/check-code-style
 
+cppcheck:
+  stage: 'check'
+  image: alpine:latest
+  allow_failure: true
+  before_script:
+    - apk update && apk add cppcheck
+  script:
+    - cppcheck --enable=all --suppress=variableScope --suppress=unusedFunction --force -q . 
--error-exitcode=1 --library=gtk
+
 variables:
   BUNDLE: 'epiphany-git.flatpak'