chore(ci): mark smoke tests as allowed failures on travis

They fail due to IE flakiness most of the time, see angular#1052.

.travis.yml

@@ -2,15 +2,15 @@ language: node_js
 node_js:
   - "0.10"
 
-env:
-  matrix:
-    - JOB=smoke
-    - JOB=suite
+matrix:
+  - env: JOB=suite
+  allow_failures:
+    - env: JOB=smoke
   global:
-    - SAUCE_USERNAME=angular-ci
-    - SAUCE_ACCESS_KEY=9b988f434ff8-fbca-8aa4-4ae3-35442987
-    - LOGS_DIR=/tmp/protractor-build/logs
-    - BROWSER_PROVIDER_READY_FILE=/tmp/sauce-connect-ready
+    - env: SAUCE_USERNAME=angular-ci
+    - env: SAUCE_ACCESS_KEY=9b988f434ff8-fbca-8aa4-4ae3-35442987
+    - env: LOGS_DIR=/tmp/protractor-build/logs
+    - env: BROWSER_PROVIDER_READY_FILE=/tmp/sauce-connect-ready
 
 before_script:
   - mkdir -p $LOGS_DIR