remove unneeded requirements.txt

.travis.yml

@@ -1,20 +1,20 b''
 # http://travis-ci.org/#!/ipython/ipython
 language: python
 python:
     - 3.5
     - 3.4
     - 3.3
     - 2.7
 sudo: false
 before_install:
     - git clone --quiet --depth 1 https://github.com/minrk/travis-wheels travis-wheels
     - 'if [[ $GROUP != js* ]]; then COVERAGE=""; fi'
 install:
-    - pip install -f travis-wheels/wheelhouse -r requirements.txt -e file://$PWD#egg=ipython[test]
+    - pip install -f travis-wheels/wheelhouse -e file://$PWD#egg=ipython[test]
     - pip install codecov
 script:
     - cd /tmp && iptest --coverage xml && cd -
 after_success:
     - cp /tmp/ipy_coverage.xml ./
     - cp /tmp/.coverage ./
     - codecov