update to run e2e tests on the stable branch for the cron job (#1730)

Author: jakemac53

.travis.yml

@@ -61,6 +61,11 @@ jobs:
       script: ./tool/travis.sh test_06
       env: PKG="_test"
       dart: be/raw/latest
+    - stage: e2e_test_cron
+      name: "SDK: stable - DIR: _test - TASKS: pub run test"
+      script: ./tool/travis.sh test_06
+      env: PKG="_test"
+      dart: stable
     - stage: analyze_and_format
       name: "SDK: dev - DIR: _test_common - TASKS: dartanalyzer --fatal-infos --fatal-warnings ."
       script: ./tool/travis.sh dartanalyzer

_test/.mono_repo.yml

@@ -17,3 +17,4 @@ stages:
     - test:
       dart:
         - be/raw/latest
+        - stable