Update CI & README

Author: quinnj

.github/workflows/ci.yml

@@ -0,0 +1,67 @@
+name: CI
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+    tags: '*'
+jobs:
+  test:
+    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '1.0'
+          - '1' # automatically expands to the latest stable 1.x release of Julia
+          - 'nightly'
+        os:
+          - ubuntu-latest
+        arch:
+          - x64
+        include:
+          - os: windows-latest
+            version: '1'
+            arch: x86
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.version }}
+          arch: ${{ matrix.arch }}
+      - uses: actions/cache@v1
+        env:
+          cache-name: cache-artifacts
+        with:
+          path: ~/.julia/artifacts
+          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-test-${{ env.cache-name }}-
+            ${{ runner.os }}-test-
+            ${{ runner.os }}-
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v1
+        with:
+          file: lcov.info
+# docs:
+#   name: Documentation
+#   runs-on: ubuntu-latest
+#   steps:
+#     - uses: actions/checkout@v2
+#     - uses: julia-actions/setup-julia@v1
+#       with:
+#         version: '1'
+#     - run: |
+#         julia --project=docs -e '
+#           using Pkg
+#           Pkg.develop(PackageSpec(path=pwd()))
+#           Pkg.instantiate()'
+#     - run: julia --project=docs docs/make.jl
+#       env:
+#         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+#         DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}

.travis.yml

@@ -1,5 +1,8 @@
 # SentinelArrays.jl
 
+[![CI](https://github.com/JuliaData/SentinelArrays.jl/workflows/CI/badge.svg)](https://github.com/JuliaData/SentinelArrays.jl/actions?query=workflow%3ACI)
+[![codecov](https://codecov.io/gh/JuliaData/SentinelArrays.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/JuliaData/SentinelArrays.jl)
+
 *Array types that can use sentinel values of the element type for special values*
 
 ## Installation