[setup.py]: move the module to test requirement (#1542)

bug introduced in #1393

Signed-off-by: Guohan Lu <lguohan@gmail.com>

Author: lguohan

setup.py

@@ -173,7 +173,8 @@
     tests_require = [
         'pytest',
         'mockredispy>=2.9.3',
-        'sonic-config-engine'
+        'sonic-config-engine',
+        'deepdiff==5.2.3'
     ],
     classifiers=[
         'Development Status :: 3 - Alpha',