remove test from prepare script

Merge pull request ethereumjs#482 from ethereumjs/new-release-v300

New release v3.0.0

Merge pull request ethereumjs#436 from ethereumjs/new-release-v260

New release v2.6.0 (Petersburg/Goerli)

Merge pull request ethereumjs#419 from ethereumjs/new-release-v251

New release v2.5.1

Merge pull request ethereumjs#394 from ethereumjs/new-release-v250

New release v2.5.0

Merge pull request ethereumjs#321 from ethereumjs/new-release-v240

New release v2.4.0

Merge pull request ethereumjs#296 from ethereumjs/new-release-v235

New release v2.3.5

Merge pull request ethereumjs#291 from ethereumjs/new-release-234

New release v2.3.4

Merge pull request ethereumjs#259 from ethereumjs/new-release-v233

New release v2.3.3

Merge pull request ethereumjs#230 from ethereumjs/new-release-232

[Release] New release v2.3.2