github: Replace Travis CI with github actions

We define 1 workflow with 2 jobs: One for the regular build and another
one for creating a release and uploading the corresponding assets.
They both run conditionally, depending on the gihtub event that triggered
the action.

Fixes: #825

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

.github/workflows/build.yaml

@@ -0,0 +1,54 @@
+name: Cloud Hypervisor Actions
+on: [push, create]
+
+jobs:
+  build:
+    if: github.event_name == 'push'
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Code checkout
+        uses: actions/checkout@v2
+      - name: Install Rust toolchain (stable)
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: stable
+            override: true
+
+      - name: Build
+        run: cargo build --release
+
+  release:
+    if: github.event_name == 'create' && github.event.ref_type == 'tag'
+    name: Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Code checkout
+        uses: actions/checkout@v2
+      - name: Install Rust toolchain (stable)
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: stable
+            override: true
+      - name: Build
+        run: cargo build --release
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: true
+          prerelease: true
+      - name: Upload Release Asset
+        id: upload-release-asset
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: target/release/cloud-hypervisor
+          asset_name: cloud-hypervisor
+          asset_content_type: application/octet-stream

.travis.yml

@@ -1,16 +0,0 @@
-language: rust
-
-rust:
-  - stable
-
-script:
-  - cargo build --release
-  
-deploy:
-  provider: releases
-  api_key: $GITHUB_OAUTH_TOKEN
-  file: target/release/cloud-hypervisor
-  skip_cleanup: true
-  draft: true
-  on:
-    tags: true