Merge pull request #78 from buildkite-plugins/renovate/shellcheck-1.x

chore(deps): update buildkite plugin shellcheck to v1.4.0

Author: pzeballos

buildkite.yaml

@@ -1,7 +1,7 @@
 steps:
   - label: ":shell: Shellcheck"
     plugins:
-      - shellcheck#v1.3.0:
+      - shellcheck#v1.4.0:
          files: hooks/**
 
   - label: ":sparkles:"