Switch to github workflows (#1)

Author: dpwiz

.github/workflows/workflow.yml

@@ -0,0 +1,24 @@
+on: [push, pull_request]
+
+name: build
+
+jobs:
+  build: # TODO: split by OS
+    strategy:
+      fail-fast: false
+      max-parallel: 3
+      matrix:
+        ghc: ['8.10', '9.0', '9.2']
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    name: ${{ matrix.os }} ghc-${{ matrix.ghc }}
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: haskell/actions/setup@v1
+        with:
+          ghc-version: ${{ matrix.ghc }}
+          cabal-version: ${{ matrix.cabal }}
+
+      - run: cabal build --only-dependencies -j2
+      - run: cabal build

.travis.yml

@@ -1,6 +1,5 @@
 # aeson-tiled
-[![Build Status](https://travis-ci.org/schell/aeson-tiled.svg?branch=master)](https://travis-ci.org/schell/aeson-tiled)
-[![Build Status](https://ci.appveyor.com/api/projects/status/github/schell/aeson-tiled)]((https://ci.appveyor.com/api/projects/status/github/schell/aeson-tiled))
+
 [![Hackage](https://img.shields.io/hackage/v/aeson-tiled.svg)](https://hackage.haskell.org/package/aeson-tiled)
 
 `aeson-tiled` is the spiritual successor to `htiled`. `htiled` uses `hxt` which relies