Operations tests

The different kinds of operations ("transactions") are tested individually with test handlers.

Test case format

`meta.yaml`

description: string    -- Optional description of test case, purely for debugging purposes.
                          Tests should use the directory name of the test case as identifier, not the description.
bls_setting: int       -- see general test-format spec.

`pre.yaml`

A YAML-encoded BeaconState, the state before applying the operation.

Also available as pre.ssz.

`<operation-name>.yaml`

A YAML-encoded operation object, e.g. a ProposerSlashing, or Deposit.

Also available as <operation-name>.ssz.

`post.yaml`

A YAML-encoded BeaconState, the state after applying the operation. No value if operation processing is aborted.

Also available as post.ssz.

Condition

A handler of the operations test-runner should process these cases, calling the corresponding processing implementation. This excludes the other parts of the block-transition.

Operations:

`operation-name`	`operation-object`	`input name`	`processing call`
`attestation`	`Attestation`	`attestation`	`process_attestation(state, attestation)`
`attester_slashing`	`AttesterSlashing`	`attester_slashing`	`process_attester_slashing(state, attester_slashing)`
`block_header`	`Block`	`block`	`process_block_header(state, block)`
`deposit`	`Deposit`	`deposit`	`process_deposit(state, deposit)`
`proposer_slashing`	`ProposerSlashing`	`proposer_slashing`	`process_proposer_slashing(state, proposer_slashing)`
`voluntary_exit`	`VoluntaryExit`	`voluntary_exit`	`process_voluntary_exit(state, voluntary_exit)`

Note that block_header is not strictly an operation (and is a full Block), but processed in the same manner, and hence included here.

The resulting state should match the expected post state, or if the post state is left blank, the handler should reject the input operation as invalid.