switch sign_client to setupfile

Author: adorton-adobe

setup.py

@@ -57,7 +57,7 @@
           'click-default-group',
           'configparser==3.7.4',
           'schema==0.7.2',
-          'sign-client'
+          'sign-client~=0.2.1',
       ],
       extras_require={
           ':sys_platform=="linux" or sys_platform=="linux2"': [