use GitHub CI (#441)

* Create elixir.yml

* use matrix

* fix version

* exclude latest elixir with old otp

elixir 1.10+ requires otp 21+

* exclude versions that are doomed to fail

* forget about it

* Delete .travis.yml

* update workflow

* add caching

* fix caching

.github/workflows/elixir.yml

@@ -0,0 +1,34 @@
+name: Elixir CI
+
+on: push
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        elixir: [1.10.4, 1.9, 1.8]
+        otp: [23.1, 22.3, 21.3]
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup elixir
+        uses: actions/setup-elixir@v1
+        with:
+          elixir-version: ${{ matrix.elixir }}
+          otp-version: ${{ matrix.otp }}
+
+      - name: Restore dependencies cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            deps
+            _build
+          key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-mix-
+
+      - name: Install Dependencies
+        run: mix deps.get
+
+      - name: Run Tests
+        run: mix test

.travis.yml

@@ -1,33 +0,0 @@
-language: elixir
-sudo: false
-cache:
-  directories:
-    - _build
-    - deps
-branches:
-  only:
-    - master
-elixir: '1.10'
-otp_release: '23.1'
-stages:
-  - test
-  - name: inch
-    if: type = push
-jobs:
-  include:
-    - stage: test
-
-    - opt_release: '22.3'
-      elixir: '1.9'
-
-    - otp_release: '21.3'
-      elixir: '1.8'
-
-    - stage: inch
-      script:
-        - mix deps.get --only docs
-        - MIX_ENV=docs mix inch.report
-
-notifications:
-  recipients:
-    - steve@stevedomin.com