the new SSL certs routine requires cryptography>=1.0.2 to make RSAPublicNumbers hashable

an earlier problem about --upgrade (de34d0d3) seemed to be just a local problem on my box, so going back to unpinned >= requirement specs

https://discourse.mailinabox.email/t/upgrade-to-v0-13b-broke-admin/876

setup/management.sh

@@ -7,7 +7,7 @@ echo "Installing Mail-in-a-Box system management daemon..."
 # build-essential libssl-dev libffi-dev python3-dev: Required to pip install cryptography.
 apt_install python3-flask links duplicity libyaml-dev python3-dnspython python3-dateutil \
 	build-essential libssl-dev libffi-dev python3-dev python-pip
-hide_output pip3 install --upgrade rtyaml email_validator==1.0.0 idna>=2.0.0 cryptography==1.0 boto
+hide_output pip3 install --upgrade rtyaml email_validator>=1.0.0 idna>=2.0.0 cryptography>=1.0.2 boto
 
 # duplicity uses python 2 so we need to use the python 2 package of boto
 hide_output pip install --upgrade boto