Add "verify" as an option to create_client_from_env and the XMLRPC and REST transports

[sudorandom]

Expected Behavior

This code should now stand up a transport where verify=False (by default) for each request.

client = SoftLayer.create_client_from_env(verify=False)
account = client.call('SoftLayer', 'getObject') # no, don't verify
account = client.call('SoftLayer', 'getObject', verify=True)  # yes, verify
account = client.call('SoftLayer', 'getObject', verify=False) # no, don't verify

# This should default to verifying each request:
client = SoftLayer.create_client_from_env()
account = client.call('SoftLayer', 'getObject')  # yes, verify
account = client.call('SoftLayer', 'getObject', verify=False) # no, don't verify
account = client.call('SoftLayer', 'getObject', verify=True) # yes, verify