Move CI to Github action (#89)

Author: dkarrasch

.github/workflows/ci.yml

@@ -0,0 +1,31 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  test:
+    name: Julia ${{ matrix.version }} - ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        version:
+          - '1.0'
+          - '1'
+          - 'nightly'
+        os:
+          - ubuntu-latest
+          - macOS-latest
+          - windows-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: julia-actions/setup-julia@latest
+        with:
+          version: ${{ matrix.version }}
+      - uses: julia-actions/julia-buildpkg@latest
+      - uses: julia-actions/julia-runtest@latest
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v1

.travis.yml

@@ -1,8 +1,7 @@
 # LinearMaps
 
-[![Build Status](https://travis-ci.org/Jutho/LinearMaps.jl.svg?branch=master)](https://travis-ci.org/Jutho/LinearMaps.jl)
+![Build status](https://github.com/Jutho/LinearMaps.jl/workflows/CI/badge.svg)
 [![License](http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat)](LICENSE.md)
-[![Coverage Status](https://coveralls.io/repos/github/Jutho/LinearMaps.jl/badge.svg?branch=master)](https://coveralls.io/github/Jutho/LinearMaps.jl?branch=master)
 [![codecov.io](http://codecov.io/github/Jutho/LinearMaps.jl/coverage.svg?branch=master)](http://codecov.io/github/Jutho/LinearMaps.jl?branch=master)
 
 A Julia package for defining and working with linear maps, also known as linear