Added travis again

Author: schickling

.travis.yml

@@ -0,0 +1,30 @@
+os: osx
+osx_image: xcode9.2
+
+language: node_js
+node_js: "8"
+
+cache:
+  directories:
+  - node_modules
+  - $HOME/.cache/electron
+  - $HOME/.cache/electron-builder
+
+install:
+  - |
+    security create-keychain -p travis build.keychain
+    security default-keychain -s build.keychain
+    security unlock-keychain -p travis build.keychain
+    echo $CERTIFICATE_OSX_P12 | base64 --decode > certificate.p12
+    security import certificate.p12 -k build.keychain -P $CERTIFICATE_OSX_PASSWORD -T /usr/bin/codesign
+    security set-key-partition-list -S apple-tool:,apple: -s -k travis build.keychain
+  - cd packages/graphql-playground-electron
+  - yarn install
+  - yarn release
+
+notifications:
+  email: false
+
+branches:
+  except:
+    - "/^v\\d+\\.\\d+\\.\\d+$/"