Create an integration test where we make requests to lightwalletd backed by zebrad

[dconnolly]

Motivation

We want to check that Zebra actually works with lightwalletd.

Tasks

Stage 1

• Compile lightwalletd binary in CI from the ZecWallet fork's master branch

The test should pass if lightwalletd compiles.

Stage 2

• Add a lightwalletd integration test for the RPC port, here is an example
• Run lightwalletd_integration acceptance test in CI after setting ZEBRA_TEST_LIGHTWALLETD

Test Design

The test should pass if we get a "missing RPC" error for the next RPC method that lightwalletd calls after getblockchaininfo.

(Zebra already has a getblockchaininfo stub. It is ok if getblockchaininfo is missing some fields, Go will fill in zero-valued data.)

Follow-Up Tasks

• Add lightwalletd full sync integration test #3511

[dconnolly]

Hey team! Please add your planning poker estimate with ZenHub @teor2345 @upbqdn @oxarbitrage @jvff @ftm1000 @conradoplg

[teor2345]

I added a link to a manual test to the ticket description:
#3589 (comment)

[teor2345]

We will need to set ZEBRA_TEST_LIGHTWALLETD to get this test to run, after PR #3627 merges.

[teor2345]

@gustavovalverde I just updated the ticket to use the ZecWallet fork's master branch. Can you make that change in CI?

[gustavovalverde]

@teor2345 Sure.

[gustavovalverde]

Fixed by #3619 and #3657