Update install-db.sh

use xenial instead of bionic

Author: gabor-boros

scripts/install-db.sh

@@ -5,8 +5,8 @@ set -u
 
 export DISTRIB_CODENAME=$(lsb_release -sc)
 
-apt-key adv —keyserver keys.gnupg.net —recv-keys "539A 3A8C 6692 E6E3 F69B 3FE8 1D85 E93F 801B B43F"
-echo "deb https://download.rethinkdb.com/repository/ubuntu-bionic bionic main" | sudo tee /etc/apt/sources.list.d/rethinkdb.list
+apt-key adv --keyserver keys.gnupg.net --recv-keys "539A 3A8C 6692 E6E3 F69B 3FE8 1D85 E93F 801B B43F"
+echo "deb https://download.rethinkdb.com/repository/ubuntu-xenial xenial" > /etc/apt/sources.list.d/rethinkdb.list
 
 sudo apt-get update --option Acquire::Retries=100 --option Acquire::http::Timeout="300"
 sudo apt-get install -y --option Acquire::Retries=100 --option Acquire::http::Timeout="300" rethinkdb