Test building the example apps in Travis

Summary:
Closes #1180.
Closes #1181

Reviewed By: wincent

Differential Revision: D3366138

Pulled By: steveluscher

fbshipit-source-id: d29ed9e9ac0dddd6801d9786be68cc3678e7adfb

.travis.yml

@@ -6,11 +6,25 @@ node_js:
 - '6'
 install: true
 env:
+- BUILD_EXAMPLE=examples/relay-treasurehunt
+- BUILD_EXAMPLE=examples/star-wars
+- BUILD_EXAMPLE=examples/todo
+- BUILD_EXAMPLE=examples/TodoMVC
 - TEST=.
 - TEST=scripts/babel-relay-plugin
 - TYPECHECK=.
 - TYPECHECK=scripts/babel-relay-plugin
+matrix:
+  allow_failures:
+  - env: BUILD_EXAMPLE=examples/relay-treasurehunt
+  - env: BUILD_EXAMPLE=examples/star-wars
+  - env: BUILD_EXAMPLE=examples/todo
+  - env: BUILD_EXAMPLE=examples/TodoMVC
 script:
+- |
+    if [ $BUILD_EXAMPLE ]; then
+      cd $BUILD_EXAMPLE && npm install && npm run update-schema
+    fi
 - |
     if [ $TEST ]; then
       cd $TEST && npm install && npm run jest -- --runInBand --no-watchman