ci(travis): run shellcheck during lint job

* Automated using myii/ssf-formula#106

.travis.yml

@@ -35,6 +35,9 @@ jobs:
       name: 'Lint: salt-lint, yamllint, rubocop & commitlint'
       before_install: 'skip'
       script:
+        # Run `shellcheck`
+        - git ls-files | grep '\.sh$\|\.bash$\|\.ksh$'
+                       | xargs shellcheck
         # Install and run `salt-lint`
         - pip install --user salt-lint
         - git ls-files | grep '\.sls$\|\.jinja$\|\.j2$\|\.tmpl$\|\.tst$'

pre-commit_semantic-release.sh

@@ -14,9 +14,9 @@ sed -i -e "s_^\(version:\).*_\1 ${1}_" FORMULA
 sudo -H pip install m2r
 
 # Copy and then convert the `.md` docs
-cp *.md docs/
-cd docs/
-m2r --overwrite *.md
+cp ./*.md docs/
+cd docs/ || exit
+m2r --overwrite ./*.md
 
 # Change excess `H1` headings to `H2` in converted `CHANGELOG.rst`
 sed -i -e '/^=.*$/s/=/-/g' CHANGELOG.rst