Add different networks.

[rockfridrich]

Add different networks as a wrappers for SimpleNetwork, fix tests and add testing address for tests
Closes #9

[0crat]

@Biboran/z please, pay attention to this pull request

[0crat]

Job #35 is now in scope, role is REV

[rockfridrich]

@Biboran should we place available methods validation to Network object?
For example, parity_nextNonce can be called only with ParityNework.
Also there could be different responses based on network you are using

[abdulowork]

InfuraChain seems like a pure DTO to me. It doesn't serve a good purpose and violates encapsulation by exposing isTest flag which is a bad idea. If something is intended for testing it should fit into interface polymorphically without need to expose such flags.

Could you please outline what problem is it supposed to solve? We can think on a better design together.

[abdulowork]

@rockfridrich let's forgo Parity in this PR. Could you please create a separate issue and promptly describe how working with Parity would be different from working with Geth.

[0crat]

The job #35 is now out of scope