Replace Travis CI with GitHub Actions

* Use GH Actions Matrices for multi-OS & multi-shell testing
* Drop helper script for installing zsh on Linux
    - Should be available by default on ubuntu-latest

.github/workflows/test.yml

@@ -0,0 +1,33 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+        test_shell:
+          - bash
+          - zsh
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Test
+        uses: sudo-bot/action-shunit2@latest
+        env:
+          TEST_SHELLS: ${{ matrix.test_shell }}
+        with:
+          cli: ./run_tests.sh

.travis.yml

@@ -1,18 +0,0 @@
-os:
-  - linux
-  - osx
-
-env:
-  - TEST_SHELLS=bash
-  - TEST_SHELLS=zsh
-
-sudo: required
-
-install:
-  - ./test/support/travisci_deps.sh
-
-before_script:
-  - echo -e "test_repo_11\ntest_repo_1" | sort
-
-script:
-  - ./run_tests.sh

test/support/travisci_deps.sh

@@ -1,32 +0,0 @@
-#!/usr/bin/env bash
-# Installs dependencies for travis-ci environments.
-
-# Install dependencies, which looks to be just bash & zsh.
-#
-# Darwin has zsh preinstalled already, so only need to install on Ubuntu.
-#
-# Note: $TRAVIS_OS_NAME will only be set on text boxes with multi-os enabled,
-# so use negation test so it will fail gracefully on normal Travis linux setup.
-if [[ "$TRAVIS_OS_NAME" != "osx" ]]; then
-
-  # okay, so we know we're probably on a linux box (or at least not an osx box)
-  # at this point. do we need to install zsh? let's say the default case is no:
-  needs_zsh=false
-
-  # check if zsh is listed in the TEST_SHELLS environment variable, set by
-  # our travis-ci build matrix.
-  if [[ $TEST_SHELLS =~ zsh ]]; then needs_zsh=true; fi
-
-  # if there is NO $TEST_SHELLS env variable persent (which should never happen,
-  # but maybe someone has been monkeying with the .travis.yml), run_tests.sh is
-  # going to fall back onto the default of testing everything, so we need zsh.
-  if [[ -z "$TEST_SHELLS" ]]; then needs_zsh=true; fi
-
-  # finally, we install zsh if needed!
-  if $needs_zsh; then
-    sudo apt-get update
-    sudo apt-get install zsh
-  else
-    echo "No deps required."
-  fi
-fi