Add more NICs to nodes in sample_environment.json

Some nodes in sample_environment.json contains only one NIC. So if somebody
tries to run fake deploy process he'll fail because of error:

    Some untagged networks are assigned to the same physical interface.
    You should assign them to different physical interfaces

Since now, all the nodes have at least two NICs.

Change-Id: I2901809063701a89f2f7bcd5a419e97759580da3
Closes-Bug: #1271129
Merge "Add more NICs to nodes in sample_environment.json"