Fix issue where docker needs more recent packages

The following packages have unmet dependencies:
 docker-ce : Depends: libseccomp2 (>= 2.3.0) but 2.2.3-3ubuntu3 is to be installed
E: Unable to correct problems, you have held broken packages.

scripts/installer.sh

@@ -54,6 +54,12 @@ if [[ $(docker version --format {{.Client.Version}}) != "18.03.0-ce" ]]; then
         sleep 1
     done
 
+    # the latest docker might need newer packages
+    while ! apt update -y; do
+        echo "==> installer: Failed to update packages. Retry"
+        sleep 1
+    done
+
     while ! apt install -y /tmp/docker.deb; do
         echo "==> installer: Failed to install docker. Retry"
         sleep 1