upgrade-to-new-actions (#170)

Added GH Actions CI and removed Travis.

.github/main.workflow

-workflow "Publish to RubyGems" {
-  on = "release"
-  resolves = [
-    "Publish to GPR",
-    "Publish to Ruby Gems",
-  ]
-}
-
-action "Build from Gemspec" {
-  uses = "scarhand/actions-ruby@master"
-  runs = "gem build just-the-docs.gemspec"
-}
-
-action "Publish to Ruby Gems" {
-  uses = "scarhand/actions-ruby@master"
-  needs = ["Build from Gemspec"]
-  runs = "gem push *.gem"
-  secrets = ["RUBYGEMS_AUTH_TOKEN"]
-}
-
-action "Publish to GPR" {
-  uses = "scarhand/actions-ruby@master"
-  needs = ["Build from Gemspec"]
-  secrets = ["GPR_AUTH_TOKEN"]
-  runs = " gem push --key [\"GPR_AUTH_TOKEN\"] --host https://rubygems.pkg.github.com/pmarsceill *.gem"
-}

.github/workflows/ci.yml

+on: [push]
+
+name: CI
+
+jobs:
+
+  jekyll:
+    name: Build Jekyll site
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: actions/checkout@master
+
+    - name: Build the site in the jekyll/builder container
+      run: |
+        docker run --rm \
+        --volume="${{ github.workspace }}:/srv/jekyll" \
+        jekyll/builder:3.8.5 /bin/bash -c "chmod 777 /srv/jekyll && jekyll build"
+        
+  css:
+    name: Stylelint
+    runs-on: ubuntu-latest
+    steps:
+    
+    - uses: actions/checkout@master
+
+    - name: Use Node.js 10.x
+      uses: actions/setup-node@v1
+      with:
+        version: 10.x
+
+    - name: npm install, build, and test
+      run: |
+        npm install
+        npm test

.travis.yml

-language: ruby
-rvm:
-  - 2.3.0
-env:
-  - TRAVIS_NODE_VERSION="9.3.0"
-
-install:
-  - npm install
-  - gem install bundler --version '>=1.17.1'
-  - bundle install
-
-script:
-  - npm run test
-  - bundle exec jekyll build