Disable Fuzz testing

[niconiconi]

Fuzz testing tend to feed invalid input to the proof system,

For example, when implementing integer division with Hint functions, the fuzz testing tends to feed 0 to the divisor and causing divided by zero error. (Panic in the hint function.)

A hint function failure should be a failed proof instead of directly terminate the Go program.

Is there any way to disable fuzz testing?

[ivokub]

There is a draft PR #296 which implements the testing option to disable fuzzing. The long-term idea is to remove fuzzing from the assert.ProverSucceeded method and implement a different test suite.

I rebased the PR on top of develop, so if you just run your tests on top of the feat/nofuzzing branch with test.NoFuzzing() test option, then it should skip the fuzzing tests for now.