Travis CI: Try enabling Coverity scan

.travis.yml

@@ -4,6 +4,18 @@ notifications:
   channels: "anathema.us.nu#anathema"
   use_notice: true
   skip_join: true
+env:
+ global:
+  - secure: "kE1g19PD3K/VlE9VRhCVIyKiliJ6BdPhfNd7t1QB0vFeKT5BHd6SjF1tz+1ei/LAij0NvekMddZ3HS8wQpr7rpiVcyyPuLCgE6t1++86A4ZE+jJ7XKnonwaGwdWll6d42w6buWh0yuFXU/DaZoAi2p2ILEGxvnF+YSVliWZPZWk="
+addons:
+ coverity_scan:
+  project:
+   name: "pjanouch/autistdraw"
+   description: "Terminal drawing application"
+  notification_email: p.janouch@gmail.com
+  build_command_prepend: "cmake .. -DCMAKE_BUILD_TYPE=Release"
+  build_command: "make"
+  branch_pattern: coverity_scan
 compiler:
  - clang
  - gcc