Update .travis.yml

This *might* fix it enough for all tests to run (maybe?)

.travis.yml

@@ -3,8 +3,10 @@ compiler:
   - gcc
 
 before_script:
-  - sudo apt-get install python3
+  - sudo add-apt-repository -y ppa:fkrull/deadsnakes
+  - sudo apt-get update -qq
+  - sudo apt-get install -y python3.3
 
 script:
   - make -C unix
-  - cd tests && ./run-tests basics/[a-eistuw]*.py
+  - cd tests && MICROPY_CPYTHON3=python3.3 ./run-tests