Add a whitespace check script

This patch sets put in whitespace check against all files except .tgz,
files in hidden directory or things in the doc/build folder.  Enforcing
the cleanup work in [0]. Also fixed two readmes' trailing blank spaces.

[0] https://review.openstack.org/#/c/466409/

Change-Id: I21ee232e4d502ca2db9dbf012624d6552d0f7ad2

tools/gate/setup_gate.sh

@@ -24,6 +24,11 @@ export HOST_OS=${ID}
 source ${WORK_DIR}/tools/gate/funcs/network.sh
 source ${WORK_DIR}/tools/gate/funcs/helm.sh
 
+# Moving the ws-linter here to avoid it blocking all the jobs just for ws
+if [ "x$INTEGRATION_TYPE" == "xlinter" ]; then
+  bash ${WORK_DIR}/tools/gate/whitespace.sh
+fi
+
 # We setup the network for pre kube here, to enable cluster restarts on
 # development machines
 net_resolv_pre_kube

tools/gate/whitespace.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+set -ex
+
+folder='.'
+if [[ $# -gt 0 ]] ; then
+  folder="$1";
+fi
+
+res=$(find $folder \
+      -not -path "*/\.*" \
+      -not -path "*/doc/build/*" \
+      -not -name "*.tgz" \
+      -type f -exec egrep -l " +$" {} \;)
+
+if [[ -z $res ]] ; then
+  exit 0
+else
+  echo 'Trailing space(s) found.'
+  exit 1
+fi