Removed Python 3.3-specific testing.

I believe the way things were setup before my deactivating and re-activating the virtual environment lead to it using Python 2.7 even when it said it was going to use Python 3.3. For now, I can't come up with a good way to test on Python 3 without recompiling numpy each time, which is insanely time consuming.

.travis.yml

@@ -1,13 +1,6 @@
 language: python
 python:
   - "2.7"
-  - "3.3"
-before_install:
-    - deactivate
-    - sudo apt-get update -qq
-    - sudo apt-get install -qq python3-numpy python3-scipy python3-nose python-numpy python-scipy python-nose
-    - virtualenv --system-site-packages ~/virtualenv/this
-    - source ~/virtualenv/this/bin/activate
 install:
   - "pip install -r Python/requirements.txt --use-mirrors"
 script: sh -x run_travis_tests.sh