Set the pip timeout globally for Travis

Conflicts:
	.travis.yml

.travis.yml

@@ -28,6 +28,7 @@ before_install:
     - export PYTHONWARNINGS="all"
     - export WHEELHOUSE="--no-index --find-links=http://travis-wheels.scikit-image.org/"
     - export TEST_ARGS="--exe --ignore-files=^_test -v --with-doctest --ignore-files=^setup.py$"
+    - export PIP_DEFAULT_TIMEOUT=60
     - sudo apt-get update
 
     - travis_retry tools/travis_setup.sh

tools/travis_setup.sh

@@ -24,7 +24,7 @@ if [[ $TRAVIS_PYTHON_VERSION == 2.7* ]]; then
     sed -i 's/matplotlib>=*.*.*/matplotlib==1.3.1/g' requirements.txt
 fi
 
-pip install --timeout 60 $WHEELHOUSE -r requirements.txt
+pip install $WHEELHOUSE -r requirements.txt
 
 # clean up disk space
 sudo apt-get clean