travis: Force flaky on travis, they are becoming really annoying

Flaky tests send wrong signals, and we restart anyway. We should rather track
flakiness an open issues when they become too regular.

.travis/build.sh

@@ -38,6 +38,12 @@ echo -en 'travis_fold:start:script.1\\r'
 cat config.vars
 echo -en 'travis_fold:end:script.1\\r'
 
+cat > pytest.ini << EOF
+[pytest]
+addopts=-p no:logging --color=no --force-flaky
+EOF
+
+
 if [ "$SOURCE_CHECK_ONLY" == "false" ]; then
     echo -en 'travis_fold:start:script.2\\r'
     make -j3 > /dev/null