travis: restrict pytest version to the last one supporting Python 3.3

.travis.yml

@@ -72,7 +72,7 @@ install:
   - if [ "$TYPE" == "osx" ] && [ "$PYVER" == "2" ]; then python2 -m pip install virtualenv; fi
   - if [ "$TYPE" == "osx" ] && [ "$PYVER" == "2" ]; then virtualenv venv -p python2; fi
   - if [ "$TYPE" == "osx" ]; then source venv/bin/activate; fi
-  - if [ "$TYPE" == "osx" ] || [ "$TYPE" == "linux" ]; then python -m pip install pytest hypothesis flake8 coverage codecov; fi
+  - if [ "$TYPE" == "osx" ] || [ "$TYPE" == "linux" ]; then python -m pip install "pytest<3.3.0" hypothesis flake8 coverage codecov; fi
 
 script:
   - if [ "$TYPE" == "linux" ]; then export LANG=C; export LC_ALL=C; fi

run_wine.sh

@@ -37,7 +37,7 @@ PIPEXE="$DESTDIR/Scripts/pip.exe"
 wget "https://bootstrap.pypa.io/get-pip.py"
 wine "$PYTHONEXE" get-pip.py
 rm get-pip.py
-wine "$PIPEXE" install pytest coverage hypothesis
+wine "$PIPEXE" install "pytest<3.3.0" coverage hypothesis
 
 if [ "$2" == "cmd" ]; then
     wineconsole --backend=curses