Describe the bug
When trying to run Truffle tests, the contract deployment fails, even when setting the gasPrice: 0 in the config files and deploy method in the test file.

To Reproduce
Steps to reproduce the behavior (assuming you have a network up, as shown in the README):

git clone https://github.com/ethereum-optimism/optimism.git
cd optimism && git checkout ci/examples
cd examples/Truffle-ERC20-Example
yarn
yarn truffle compile --config truffle-config-ovm.js
yarn truffle test ./test/erc20.spec.js --network optimistic_ethereum --config truffle-config-ovm.js

4. See the following error:

(I truncated the error message in the image above.)

Expected behavior
Running tests should succeed without an error being thrown, and the rest of the tests in the test file should pass.

Additional context
This issue is a carry-over from @liam's suggestion in #474 so that we stick to specific issues.