Add network list tests for ECPair/HDNode

[dcousens]

This actually fixes a bug bip32 is undefined when a networks list was passed and no valid version was found in HDNode.

[dcousens]

@fanatid please review 👍.

Thoughts on aae5db6? On the 1 hand, easier to verify the tests are actually following the path they should be (not ambiguous with the other other case).
On the other hand, its two cases a user has to be aware of, despite the fact only 1 should occur depending on whether they pass in a list or singular network parameter.

[fanatid]

@dcousens I think throwing 2 different errors is OK, first says that not one of network from networks don't match, second says that version for given|selected network is invalid.
LGTM

[fanatid]

just curious, you don't use align in if blocks?

if (version !== network.bip32.private &&
    version !== network.bip32.public) throw new Error('Invalid network version')

[dcousens]

Eh, alignment isn't that big a deal IMHO.
Its also very hard to enforce semantically so I don't bother.