Relax the install_requires, no need to exact version as long as there are no broken changes with future versions (#1530) (#1592)

Same as #1530
But for 202012 branch

Fix a previous merge/cherry-pick mistake: deepdiff should be a tests_require

Author: qiluo-msft

setup.py

@@ -152,21 +152,20 @@
     },
     install_requires=[
         'click==7.0',
-        'ipaddress==1.0.23',
-        'jsondiff==1.2.0',
-        'm2crypto==0.31.0',
-        'natsort==6.2.1',  # 6.2.1 is the last version which supports Python 2. Can update once we no longer support Python 2
-        'netaddr==0.8.0',
-        'netifaces==0.10.7',
-        'pexpect==4.8.0',
-        'requests==2.25.0',
+        'ipaddress>=1.0.23',
+        'jsondiff>=1.2.0',
+        'm2crypto>=0.31.0',
+        'natsort>=6.2.1',  # 6.2.1 is the last version which supports Python 2. Can update once we no longer support Python 2
+        'netaddr>=0.8.0',
+        'netifaces>=0.10.7',
+        'pexpect>=4.8.0',
+        'requests>=2.25.0',
         'sonic-platform-common',
         'sonic-py-common',
         'sonic-yang-mgmt',
         'swsssdk>=2.0.1',
-        'tabulate==0.8.2',
-        'xmltodict==0.12.0',
-        'deepdiff==5.2.3',
+        'tabulate>=0.8.2',
+        'xmltodict>=0.12.0',
     ],
     setup_requires= [
         'pytest-runner',