Implement shellcheck on Travis CI using the latest docker image.

TravisCI.md

@@ -20,4 +20,30 @@ script:
 
 matrix:
   fast_finish: true
+```
+
+
+***   
+
+   
+contributor ccztux says:
+
+>This is how you can implement shellcheck on Travis CI using the latest docker image:
+
+```yaml
+sudo: required
+
+language: bash
+
+services:
+  - docker
+
+before_install:
+  - docker pull koalaman/shellcheck
+
+script:
+ - docker run -v $(pwd):/scripts koalaman/shellcheck /scripts/yourscript.sh
+
+matrix:
+fast_finish: true
 ```