[dev_setup] Clear bundler config

This change clears all bundler remembered settings before attempting
an installation.
  Probably due to the huge repository size, a lot of users try copying
their repos around, despite the recommended best practice of only
copying the bare repo. This change should solve the problem of a
conflict between the dev / test group of gems and production gems for
components, say the Cloud Controller.

  The installer now prompts the user before purging those .bundle
directories, or if you want to run non-interactively, pass --all or -a
to it.

Change-Id: I04b6b9ad462546b51ab1ee11e7e8de91263372bd

dev_setup/bin/vcap_dev_setup

@@ -84,6 +84,16 @@ function run_cmd () {
   fi
 }
 
+function clear_bundler_settings () {
+  # Do we have a Bundler problem?
+  find $CLOUDFOUNDRY_HOME/vcap -type d -name .bundle | grep -Fq .bundle || return 0
+  if [ "$ALL" != true ]; then
+    read -p "Remembered Bundler options could cause you troubles, do you want me to clear them for you? [Y/n]"
+    [[ $REPLY =~ ^[nN] ]] && return 0
+  fi
+  (cd $CLOUDFOUNDRY_HOME/vcap && rake bundler:reset || find -type d -name .bundle -prune -exec rm -r {} \; )
+}
+
 # Check if we have access to the web
 run_cmd apt-get $APT_CONFIG install -qym wget
 if [ $? -ne 0 ]; then
@@ -118,6 +128,8 @@ if [ ! -d $CLOUDFOUNDRY_HOME/vcap ]; then
     echo "Unable to clone cloudfoundry repo."
     exit 1
   fi
+else
+  clear_bundler_settings
 fi