Bump pymongo version to support mongo6 (#17)

* Bump Version

* Update requirements.txt

Author: avinashtanniru

requirements.txt

@@ -1,6 +1,6 @@
 multiprocessing
 Fabric==1.14.0
-pymongo==3.6.0
+pymongo==3.12.3
 pynsca==1.5
 PyYAML==3.12
 boto==2.48.0