Use Github actions instead of Travis and Appveyor

Author: aminya

.github/workflows/ci.yml

@@ -0,0 +1,61 @@
+name: CI
+on:
+  - push
+  - pull_request
+
+jobs:
+
+  Test:
+    if: "!contains(github.event.head_commit.message, '[skip ci]')"
+    name: Julia ${{ matrix.julia_version }} - ${{ matrix.os }} - ${{ matrix.arch }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - {os: ubuntu-latest, julia_version: "1.3", julia_arch: x64, atom_channel: stable }
+          - {os: windows-latest, julia_version: "1.3", julia_arch: x64, atom_channel: stable }
+          - {os: ubuntu-latest, julia_version: "nightly", julia_arch: x64, atom_channel: stable }
+          - {os: windows-latest, julia_version: "nightly", julia_arch: x64, atom_channel: stable }
+    steps:
+      - uses: actions/checkout@v2
+      - uses: UziTech/action-setup-atom@v1
+          with:
+            channel: ${{ matrix.config.atom_channel }}
+      - uses: julia-actions/setup-julia@latest
+        with:
+          version: ${{ matrix.config.julia_version }}
+          arch: ${{ matrix.config.julia_arch }}
+      - name: Versions
+        run: |
+          julia -v
+          atom -v
+          apm -v
+          npm -v
+      - name: Install APM dependencies
+        run: apm ci     # or apm install
+      - name: Julia CI
+        run:  julia -e 'include("ci/packages.jl")'
+        shell: bash
+      - name: Run tests 👩🏾‍💻
+        run: atom --test spec
+
+  Lint:
+    if: "!contains(github.event.head_commit.message, '[skip ci]')"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: '12.x'
+      - name: NPM install
+        run: npm ci
+      - name: Lint ✨
+        run: npm run lint
+
+  Skip:
+      if: contains(github.event.head_commit.message, '[skip ci]')
+      runs-on: ubuntu-latest
+      steps:
+        - name: Skip CI 🚫
+          run: echo skip ci