Issue 279 - unique path for each chains db, network, keystore to prevent collisions (#322)

* make spec.name() part of database_path preventing collisions

resolves #279

* add `id` field to `ChainSpec`

* add blank line for readability

* dot/cli: use spec_id in db_path

* dot/cli: make spec_id part of keystore_path

* dot/cli: make spec_id part of network_path

* add id field to poc-1.json chain spec

* dot/cli: spec_id -> chain_id