Add build to Travis CI configuration.

.travis.yml

@@ -7,5 +7,7 @@ before_install:
   - sudo pip3 install selenium
 jobs:
   include:
+    - stage: build
+      script: python3 utils/build/build.py
     - stage: test
       script: python3 tests/run_tests.py

utils/build/build.py

@@ -143,6 +143,7 @@ def build(files, css, html, filename, release=False):
     output(addHeaderJS(js, version), folder + filename)
 
 def main():
+    os.chdir(os.path.dirname(os.path.abspath(__file__)))  # cd to script dir
     if (len(sys.argv) > 1 and sys.argv[1] == 'release'):
         build(JS, CSS, HTML, 'pannellum', True)
     else: