Fix build #750

ci/appveyor/build.cmd

@@ -12,7 +12,7 @@ call pyuic5 --version
 pyrcc5 -version
 
 pip install -r requirements.txt
-pip install pyinstaller
+pip install pyinstaller==3.2
 pip install six
 pip install packaging
 

ci/travis/build.sh

@@ -9,7 +9,7 @@ pip install --upgrade pip
 pyenv rehash
 pip install coveralls
 pip install pytest-cov
-pip install pyinstaller
+pip install pyinstaller==3.2
 pip install PyQt5==5.8.2
 pip install -r requirements.txt
 if [ $TRAVIS_OS_NAME == "linux" ]