Integrate benchmarks with CI

[cvgw]

Requested feature A clear description of the desired feature and an example of
how it would be used.

Benchmarks should be run and have some kind of assertion/validation during CI

Why the feature is needed A clear description of how this feature is not
served by existing functionality in gomock.

To ensure that there are no major performance regressions

(Optional) Proposed solution A clear description of a proposed method for
adding this feature to gomock.
possible option https://dev.to/dannypsnl/how-to-compare-go-benchmark-in-travisci-2407

[codyoss]

Closing this issue for now. There are open issues around performance. If we see some issues arise in the future will re-evaluate.