Use GitHub Actions for unit testing on Arm arch.

The test runs on a docker container with QEMU.
This also updates TagBot.yml.

Author: kimikage

.github/workflows/TagBot.yml

@@ -1,9 +1,12 @@
 name: TagBot
 on:
-  schedule:
-    - cron: 0 * * * *
+  issue_comment:
+    types:
+      - created
+  workflow_dispatch:
 jobs:
   TagBot:
+    if: github.event_name == 'workflow_dispatch' || github.actor == 'JuliaTagBot'
     runs-on: ubuntu-latest
     steps:
       - uses: JuliaRegistries/TagBot@v1

.github/workflows/UnitTestArm.yml

@@ -0,0 +1,33 @@
+name: Unit test for Arm
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  workflow_dispatch:
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        julia-version: ['1.0', '1', 'nightly']
+        os: [ubuntu-20.04]
+        distro: [ubuntu20.04]
+        arch: [aarch64]
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: uraimo/run-on-arch-action@v1
+        with:
+          architecture: ${{ matrix.arch }}
+          distribution: ${{ matrix.distro }}
+          githubToken: ${{ github.token }}
+          install: |
+            python3 -m pip install jill --user
+            python3 -m jill install ${{ matrix.julia-version }} --confirm --upstream Official
+            ln -L /usr/bin/julia-latest /usr/bin/julia
+          run: |
+            julia --project=. --check-bounds=yes --color=yes -e 'using InteractiveUtils; versioninfo(); using Pkg; Pkg.build(); Pkg.test(coverage=true)'
+            julia -e 'using Pkg; Pkg.add("Coverage"); using Coverage; Codecov.submit_local(process_folder())'