Sometimes tests fail unexpectedly

[PopcornPaws]

For example:
thread 'test_eth_call_contract_transfer' panicked at 'called Option::unwrap() on a None value'
which means that the Http request is either not waiting for the response or it cuts it in half.

Sometimes it panics because
there is no field called 'result'
in the returned json response, so it only gets part of the json-rpc message.

[PopcornPaws]

It seems that using reqwest for http requests attenuated this issue a bit, however, it still occurs sporadically that a test fails because there's no response from the geth client.

Nevertheless, when the tests are run immediately again, they all pass.