Update apt on client computer

Fixes #1255

toolset/setup/linux/client.sh

@@ -8,8 +8,10 @@ export DEBIAN_FRONTEND=noninteractive
 ##############################
 # Prerequisites
 ##############################
+sudo apt-get -y update
+
 # WARNING: DONT PUT A SPACE AFTER ANY BACKSLASH OR APT WILL BREAK
-# Dpkg::Options avoid hangs on Travis-CI, don't affect clean systems
+# Dpkg::Options avoid hangs on Travis-CI, doesn't affect clean systems
 sudo apt-get -y install -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" \
     build-essential git libev-dev libpq-dev libreadline6-dev