Fix homebrew formula template

templates/unifi-poller.rb.tmpl

@@ -22,10 +22,18 @@ class UnifiPoller < Formula
     cd bin_path do
       system "dep", "ensure"
       system "make", "install", "VERSION=#{version}", "PREFIX=#{prefix}", "ETC=#{etc}"
+      system "mkdir", "-p", "#{var}/log/unifi-poller"
     end
   end
-
-   plist_options :startup => true
+  def caveats
+    s = <<-EOS
+  This application will not work until the config file has authentication
+  information for a Unifi Controller and an Influx Database. Edit the config
+  file at #{etc}/unifi-poller/up.conf then start the application with
+  brew services start unifi-poller ~ log file: #{var}/log/unifi-poller/log
+  The manual explains the config file options: man unifi-poller
+    EOS
+  end
 
   def plist; <<-EOS
    <?xml version="1.0" encoding="UTF-8"?>
@@ -48,10 +56,6 @@ class UnifiPoller < Formula
            <string>#{var}/log/unifi-poller/log</string>
            <key>StandardOutPath</key>
            <string>#{var}/log/unifi-poller/log</string>
-             <key>UserName</key>
-             <string>nobody</string>
-             <key>GroupName</key>
-             <string>nobody</string>
        </dict>
    </plist>
    EOS