[mod] update core deps with dev deps

.travis.yml

   - npm install -g less grunt-cli
   - ( cd searx/static/themes/oscar;npm install; cd - )
 install:
-  - ./manage.sh update_packages
   - ./manage.sh update_dev_packages
   - pip install coveralls
 script:

manage.sh

 }
 
 update_dev_packages() {
+    update_packages
     pip install --upgrade -r "$BASE_DIR/requirements-dev.txt"
 }