chore: Switch shfmt and shellcheck builds to GitHub Actions

.github/workflows/shfmt.yml

@@ -0,0 +1,20 @@
+name: Check Shell scripts
+
+on:
+  pull_request:
+    paths:
+      - "**/*.sh"
+
+jobs:
+  shfmt:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - run: docker run -v "$(pwd)":/sh -w /sh peterdavehello/shfmt:2.6.3 shfmt -sr -i 2 -l -w -ci .
+      - run: git diff --color --exit-code
+
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - run: shellcheck *.sh

.travis.yml

@@ -57,17 +57,6 @@ jobs:
       script:
         - find . -name "*.md" | xargs -n 1 markdown-link-check
 
-    - stage: Test
-      name: shfmt check
-      script:
-        - docker run -it --rm -v "$(pwd)":/sh -w /sh peterdavehello/shfmt:2.6.3 shfmt -sr -i 2 -l -w -ci .
-        - git diff --color
-        - git diff --stat=220 --color --exit-code
-
-    - stage: Test
-      name: Shell Check
-      script: shellcheck *.sh
-
     - stage: Test
       name: .travis.yml and travis.yml.template consistency
       script:

travis.yml.template

@@ -55,17 +55,6 @@ jobs:
       script:
         - find . -name "*.md" | xargs -n 1 markdown-link-check
 
-    - stage: Test
-      name: shfmt check
-      script:
-        - docker run -it --rm -v "$(pwd)":/sh -w /sh peterdavehello/shfmt:2.6.3 shfmt -sr -i 2 -l -w -ci .
-        - git diff --color
-        - git diff --stat=220 --color --exit-code
-
-    - stage: Test
-      name: Shell Check
-      script: shellcheck *.sh
-
     - stage: Test
       name: .travis.yml and travis.yml.template consistency
       script: