Install Qt5 for all

Author: hugovk

.travis/install.sh

@@ -3,7 +3,7 @@
 set -e
 
 sudo apt-get update
-sudo apt-get -qq install libfreetype6-dev liblcms2-dev python-tk\
+sudo apt-get -qq install libfreetype6-dev liblcms2-dev python-tk pyqt5-dev-tools\
                          ghostscript libffi-dev libjpeg-turbo-progs libopenjp2-7-dev\
                          cmake imagemagick libharfbuzz-dev libfribidi-dev
 
@@ -15,10 +15,7 @@ pip install -U pytest-cov
 pip install pyroma
 pip install test-image-results
 pip install numpy
-if [[ $TRAVIS_PYTHON_VERSION == 3.* ]]; then
-    sudo apt-get -qq install pyqt5-dev-tools
-    pip install pyqt5
-fi
+pip install pyqt5
 
 # docs only on Python 3.7
 if [ "$TRAVIS_PYTHON_VERSION" == "3.7" ]; then pip install -r requirements.txt ; fi