build: Upload release binary on tag

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

.travis.yml

@@ -12,3 +12,12 @@ script:
   - cargo test
   - cargo clippy --all-targets --all-features -- -D warnings
   - find . -name "*.rs" | grep -v "vendor/" | xargs rustfmt --check
+
+deploy:
+  provider: releases
+  api_key: $GITHUB_OAUTH_TOKEN
+  file: target/release/cloud-hypervisor
+  skip_cleanup: true
+  draft: true
+  on:
+    tags: true