use `pip install .[all]` on travis

can't actually use `.[all]` syntax, instead using `file://$PWD`,
but the principal is the same.

get wheels from minrk/travis-wheels to expedite installation

.travis.yml

@@ -17,11 +17,11 b' before_install:'
     - time sudo apt-get update
     - time sudo apt-get install pandoc casperjs libzmq3-dev
     # pin tornado < 4 for js tests while phantom is on super old webkit
-    - if [[ $GROUP == 'js' ]]; then pip install 'tornado<4'; fi
-    - time pip install -f https://nipy.bic.berkeley.edu/wheelhouse/travis jinja2 sphinx pygments tornado requests!=2.4.2 mock pyzmq jsonschema jsonpointer mistune
+    - git clone --quiet --depth 1 https://github.com/minrk/travis-wheels travis-wheels
+    - if [[ $GROUP == 'js' ]]; then pip install -f travis-wheels/wheelhouse 'tornado<4'; fi
     - if [[ $GROUP == 'js' ]]; then python -m IPython.external.mathjax; fi
 install:
-    - time python setup.py install -q
+    - time pip install -f travis-wheels/wheelhouse file://$PWD#egg=ipython[all]
 script:
     - cd /tmp && iptest $GROUP