Add CI testing, and CI badge to README

Author: marcom

.github/workflows/CI.yml

@@ -0,0 +1,41 @@
+name: CI
+on:
+  push:
+    branches:
+      - main
+    tags: ['*']
+  pull_request:
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+jobs:
+  test:
+    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '1.7'
+          - '1'
+        os:
+          - ubuntu-latest
+          - macOS-latest
+          - windows-latest
+        arch:
+          - x64
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.version }}
+          arch: ${{ matrix.arch }}
+      - uses: julia-actions/cache@v1
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v2
+        with:
+          files: lcov.info

README.md

@@ -1,5 +1,7 @@
 # Julia interface to LinearFold
 
+[![Build Status](https://github.com/marcom/LinearFold.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/marcom/LinearFold.jl/actions/workflows/CI.yml?query=branch%3Amain)
+
 Unofficial Julia interface to the
 [LinearFold](https://github.com/LinearFold) suite of programs for RNA
 secondary structure prediction. Please cite the applicable original