Feature/claimer new algorithm

[mpolitzer]

Updated claimer algorithm and tests.

// Algorithm for the state transition of computed claims. Possible actions are:
// - update epoch in the database
// - submit claim to blockchain
// - transition application to an invalid state
//
// 1. On startup of a clean blockchain there are no previous claims nor events.
//
//   - This configuration must submit a new computed claim.
//
//     2. Some time after the submission, the computed claim shows up as a claimSubmission
//     event in the blockchain. The claim and event must match.
//
//   - This configuration must update the epoch in the database: computed -> submitted
//
// 3. After the first epoch, additional checks must be done. Same as (1) otherwise.
// 3.1. No epoch was skipped:
//   - previous_claim.last_block < current_claim.first_block
//
// 4. After the first epoch, additional checks must be done. Same as (2) otherwise.
// 4.1. epochs are in order:
//   - previous_claim.last_block < current_claim.first_block
//
// 4.2. There are no events between the epochs
//   - next(previous_event) == current_event
//
// Other cases are errors.
//
// | n |      prev     |      curr     | action |
// |   | claim | event | claim | event |        |
// |---+-------+-------+-------+-------+--------+
// | 1 |   .   |   .   |  cc   |   .   | submit |
// | 2 |   .   |   .   |  cc   |  ce   | update |
// | 3 |  pc   |  pe   |  cc   |   .   | submit |
// | 4 |  pc   |  pe   |  cc   |  ce   | update |