add update before salt-minion install

Change-Id: Ibc952d9780060a171bc92ee0f910b3c04f973796
diff --git a/debian-8/scripts/salt.sh b/debian-8/scripts/salt.sh
index 60b50e9..4261885 100644
--- a/debian-8/scripts/salt.sh
+++ b/debian-8/scripts/salt.sh
@@ -1,4 +1,5 @@
 wget -O - https://repo.saltstack.com/apt/debian/8/amd64/2016.3/SALTSTACK-GPG-KEY.pub | sudo apt-key add -
 echo "deb http://repo.saltstack.com/apt/debian/8/amd64/2016.3 jessie main" >/etc/apt/sources.list.d/saltstack.list
+apt-get update
 apt-get -y install salt-minion
 mkdir -m700 -p /etc/salt/pki/minion
diff --git a/ubuntu-14.04/scripts/salt.sh b/ubuntu-14.04/scripts/salt.sh
index fde2b5b..91d4363 100644
--- a/ubuntu-14.04/scripts/salt.sh
+++ b/ubuntu-14.04/scripts/salt.sh
@@ -1,4 +1,5 @@
 wget -O - https://repo.saltstack.com/apt/ubuntu/14.04/amd64/2016.3/SALTSTACK-GPG-KEY.pub | sudo apt-key add -
 echo "deb http://repo.saltstack.com/apt/ubuntu/14.04/amd64/2016.3 trusty main" >/etc/apt/sources.list.d/saltstack.list
+apt-get update
 apt-get -y install salt-minion
 mkdir -m700 -p /etc/salt/pki/minion
diff --git a/ubuntu-16.04/scripts/salt.sh b/ubuntu-16.04/scripts/salt.sh
index a3c97b7..da25af5 100644
--- a/ubuntu-16.04/scripts/salt.sh
+++ b/ubuntu-16.04/scripts/salt.sh
@@ -1,4 +1,5 @@
 wget -O - https://repo.saltstack.com/apt/ubuntu/16.04/amd64/2016.3/SALTSTACK-GPG-KEY.pub | sudo apt-key add -
 echo "deb http://repo.saltstack.com/apt/ubuntu/16.04/amd64/2016.3 xenial main" >/etc/apt/sources.list.d/saltstack.list
+apt-get update
 apt-get -y install salt-minion
 mkdir -m700 -p /etc/salt/pki/minion