Unable to activate browsermob-proxy-0.3.1, because childprocess-3.0.0 conflicts with childprocess (~> 0.5) (Gem::ConflictError)

[thiagotrentin]

When I try to run the browsermob-proxy it show me this error:
Unable to activate browsermob-proxy-0.3.1, because childprocess-3.0.0 conflicts with childprocess (~> 0.5) (Gem::ConflictError)
Can anyone fix this issue or give me directions on how to solve this?