Improve testing speed

Improves testing speed by ~x3 (from ~3 min to ~1 min on my machine, parallel 12 threads):

• Load big 'router-info.json' only once, instead keep one non-mutating dict for all tests
• mock out ncc client to prevent trying to connect
• do not setup logging in tests (mostly for not creating error.log and info.log files)
• some more minor changes...