CLI: --network arg in `sl bmc create` is always string

It is possible to pass --network 1000 or --network 1000_DUAL. If 1000 is treated as int it will return error 'Invalid NIC speed specified'
Merge pull request #209 from loles/master

Fix sl bmc create --network 1000
Merge pull request #210 from sudorandom/master

Fixes Bugs with the CLI Messaging module
Fixes dictionary lookup bug. Closes #211
Merge pull request #212 from beittenc/fix_subnet_order_test

Fixes dictionary lookup bug. Closes #211
Fix to prevent double counting results in the summary_by_datacenter() function due to multiple network interfaces.
Fixing copy/paste error
Merge pull request #213 from beittenc/fix_summary_counts

Fix to prevent double counting results in summary_by_datacenter()
Addresses some code smells from landscale.io