Use stages for tests

.travis.yml

@@ -5,8 +5,12 @@ before_install:
   - npm install -g grunt-cli node-qunit-phantomjs
 before_script:
   - git clone -b develop https://github.com/ONLYOFFICE/web-apps.git ../web-apps
-script:
-  - node-qunit-phantomjs cell/.unit-tests/FormulaTests.html
-  - cd build
-  - npm install
-  - grunt --level=WHITESPACE_ONLY
+jobs:
+  include:
+    - stage: Formulas tests
+      script: node-qunit-phantomjs cell/.unit-tests/FormulaTests.html
+    - stage: Building SDK
+      script:
+        - cd build
+        - npm install
+        - grunt --level=WHITESPACE_ONLY
\ No newline at end of file