docs: update

.github/workflows/main.yml

@@ -0,0 +1,9 @@
+name: Shellcheck
+on: [push, pull_request]
+jobs:
+    build:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v1
+            - name: Run shellcheck.
+              run: shellcheck pash

.travis.yml

@@ -1,17 +0,0 @@
-language: bash
-sudo: required
-
-os:
-    - linux
-
-install:
-  # Install a custom version of shellcheck instead of Travis CI's default
-  - scversion="latest" # or "v0.4.7", or "latest"
-  - wget "https://storage.googleapis.com/shellcheck/shellcheck-${scversion}.linux.x86_64.tar.xz"
-  - tar --xz -xvf "shellcheck-${scversion}.linux.x86_64.tar.xz"
-  - shellcheck() { "shellcheck-${scversion}/shellcheck" "$@"; }
-
-script:
-    - shellcheck pash
-    # Check for lines longer than 80 chars.
-    - if grep '.\{81\}' pash; then (exit 1); else (exit 0); fi