Upgrade jsoncpp to 1.9.4
Bug: 170642246
Change-Id: Id1fae5a1b6421117f923c616718ee4b3571231e0
diff --git a/.travis_scripts/travis.before_install.linux.sh b/.travis_scripts/travis.before_install.linux.sh
new file mode 100644
index 0000000..9b556de
--- /dev/null
+++ b/.travis_scripts/travis.before_install.linux.sh
@@ -0,0 +1,8 @@
+set -vex
+
+# Preinstalled versions of python are dependent on which Ubuntu distribution
+# you are running. The below version needs to be updated whenever we roll
+# the Ubuntu version used in Travis.
+# https://docs.travis-ci.com/user/languages/python/
+
+pyenv global 3.7.1