feat(builder): add repo check script

This script parses through /deis/services and removes all
repositories that have been removed from the controller.

Author: Matthew Fisher

builder/conf.d/check-repos.toml

@@ -0,0 +1,10 @@
+[template]
+src   = "check-repos"
+dest  = "/home/git/check-repos"
+uid = 0
+gid = 0
+mode  = "0755"
+keys = [
+  "/deis/services",
+]
+reload_cmd = "/home/git/check-repos"

builder/templates/check-repos

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+listcontains() {
+    for word in $1; do
+        [[ $word = $2 ]] && return 0
+    done
+    return 1
+}
+
+cd $(dirname $0) # absolute path
+
+for repo in *.git;
+do
+    reponame="${repo%.*}"
+    if ! listcontains "{{ range $services := .deis_services }}{{ Base $services.Key }} {{ end }}" "$reponame";
+    then
+        rm -rf "$repo"
+    fi
+done