Create rake tasks & partial system user admin code

1. Create rake task import:lans to import LANs.
2. Create rake task init:vlans to intialize VLANs to populate its IP addresses.
3. Create partial system user administration code.
Enable gem bcrypt to install from github behind proxy using https
Add attribute mac_address to table addresses in ERD & add git source to Gemfile
Implement table vlans initialization with rake task init:vlans