Upgrade jsoncpp to 1.9.4

Bug: 170642246
Change-Id: Id1fae5a1b6421117f923c616718ee4b3571231e0
diff --git a/.travis_scripts/travis.install.linux.sh b/.travis_scripts/travis.install.linux.sh
new file mode 100644
index 0000000..7c5846f
--- /dev/null
+++ b/.travis_scripts/travis.install.linux.sh
@@ -0,0 +1,10 @@
+set -vex
+
+wget https://github.com/ninja-build/ninja/releases/download/v1.9.0/ninja-linux.zip
+unzip -q ninja-linux.zip -d build
+
+pip3 install meson
+echo ${PATH}
+ls /usr/local
+ls /usr/local/bin
+export PATH="${PWD}"/build:/usr/local/bin:/usr/bin:${PATH}