fix: tests of Zcash were broken

The Zcash tests were broken due to a change in the underlying
js-ipld-zcash library.

test/ipld-zcash.js

@@ -7,7 +7,7 @@ const expect = chai.expect
 chai.use(dirtyChai)
 const BlockService = require('ipfs-block-service')
 const ipldZcash = require('ipld-zcash')
-const ZcashBlock = require('zcash-bitcore-lib').Block
+const ZcashBlockHeader = require('zcash-bitcore-lib').BlockHeader
 const multihash = require('multihashes')
 const series = require('async/series')
 const each = require('async/each')
@@ -23,12 +23,10 @@ const buildZcashBlock = (header) => {
  header.time = header.time || 0
  header.bits = header.bits || 0
  header.nonce = header.nonce || Buffer.alloc(32)
- header.solution = header.solution || Buffer.alloc(0)
- const block = ZcashBlock.fromObject({
- header: header,
- transactions: []
- })
- return block
+ header.solution = header.solution || Buffer.alloc(1344)
+
+ const blockHeader = ZcashBlockHeader(header)
+ return blockHeader
 }
 
 module.exports = (repo) => {
@@ -114,7 +112,7 @@ module.exports = (repo) => {
  expect(err).to.not.exist()
  resolver.get(cid1, (err, result) => {
  expect(err).to.not.exist()
- expect(node1.header.version).to.eql(result.value.header.version)
+ expect(node1.version).to.eql(result.value.version)
  done()
  })
  })
@@ -193,7 +191,7 @@ module.exports = (repo) => {
  expect(err).to.not.exist()
  resolver.get(cid1, (err, result) => {
  expect(err).to.not.exist()
- expect(result.value.header.version).to.eql(1)
+ expect(result.value.version).to.eql(1)
  remove()
  })
  })