Fix update and update-in for higher arities

[jeroenvandijk]

Fixes #533

Added unit tests and fixed the implementation.

The GenesisTest is now failing. I guess this is expected when changing core resources?

[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.045 s <<< FAILURE! -- in convex.core.init.GenesisTest
[ERROR] convex.core.init.GenesisTest.testGenesis -- Time elapsed: 0.044 s <<< FAILURE!
org.opentest4j.AssertionFailedError: expected: <15dce0fe6903633b4ed01aa4452d7250901d5a29cbf7f2c5916c97535ee948da> but was: <6ada1415899d7135697d4823a876a4a5659c97a1d877a4d9affcd44bb5afb17c>

[mikera]

Just to be clear, this fix still very much on cards but need to be vary careful about convex.core changes on Protonet :-)