Fix linters error and enable linters zuul gate

Fix below linters errors and exclude openstack path for linter
E003 Indent not multiple of 4
E011 Then keyword is not on same line as if or elif keyword
E001 Trailing Whitespace

ignore :
E006 Line too long

Story: 2003372
Task: 24435

Change-Id: I9221fc4c07633c49d8a7cb9afa0f6a1624304cb9
Signed-off-by: Sun Austin <austin.sun@intel.com>

.zuul.yaml

@@ -3,8 +3,8 @@
     check:
       jobs:
         - openstack-tox-pep8
-
+        - openstack-tox-linters
     gate:
       jobs:
         - openstack-tox-pep8
-      
+        - openstack-tox-linters

openstack/python-glanceclient/centos/files/image-backup.sh

@@ -4,7 +4,6 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 #
-
 backup_dir="/opt/backups"
 tmp_dir="${backup_dir}/image_temp"
 
@@ -133,8 +132,7 @@ if [ $EUID -ne 0 ]; then
     exit 1
 fi
 
-if [ $# -ne 2 ] ;
-then
+if [ $# -ne 2 ]; then
     usage
     exit 0
 fi
@@ -209,4 +207,3 @@ elif [ "$1" = "import" ]; then
 else
     usage
 fi
-

tox.ini

@@ -14,6 +14,8 @@ deps = -r{toxinidir}/test-requirements.txt
 
 [testenv:linters]
 whitelist_externals = bash
+#bashate ignore
+#E006 Line too long
 commands =
   bash -c "find {toxinidir}          \
          -not \( -type d -name .?\* -prune \) \
@@ -21,11 +23,11 @@ commands =
          -not -name \*~                       \
          -not -name \*.md                     \
          -name \*.sh                          \
-         -print0 | xargs -0 bashate -v"
+         -print0 | xargs -0 bashate -v -i E006"
   bash -c "find {toxinidir}        \
-            \( -name middleware/io-monitor/recipes-common/io-monitor/io-monitor/io_monitor/test-tools/yaml/* -prune \) \
-            -o \( -name .tox -prune \)         \
-            -o -type f -name '*.yaml'       \
+            \( -path '{toxinidir}/openstack/python-heat/python-heat/templates*'  \
+            -o  -path '{toxinidir}/.tox' \) -a -prune     \
+            -o -name '*.yaml'       \
             -print0 | xargs -0 yamllint"
 
 [testenv:pep8]