Added to .travis.yml colorama and prettytable python packages

Author: PrzemekWirkus

.travis.yml

@@ -1,8 +1,8 @@
 --- 
-install: "sudo $TRAVIS_BUILD_DIR/travis/install_dependencies.sh > /dev/null"
 python: 
   - "2.7"
 script: "python workspace_tools/build_travis.py"
 install:
+  - "sudo $TRAVIS_BUILD_DIR/travis/install_dependencies.sh > /dev/null"
   - sudo pip install colorama
   - sudo pip install prettytable