Remove cryptography from requirements.txt

Author: rayluo

requirements.txt

@@ -2,8 +2,12 @@ requests==2.20.0
 PyJWT==1.7.0
 #need 2.x for Python3 support
 python-dateutil==2.1.0
+
 #1.1.0 is the first that can be installed on windows
-cryptography==3.2
+# Yet we decide to remove this from requirements.txt,
+# because ADAL does not have a direct dependency on it.
+#cryptography==3.2
+
 #for testing
 httpretty==0.8.14
 pylint==1.5.4