manage protoc versions.
go get -u github.com/garupanojisan/protocenv
protocenv creates symbolic link at $HOME/.protocenv/bin to global specified version's bin, so please set PATH as below.
export PATH=$HOME/.protocenv/bin:$PATH
# show list of all available versions
protocenv install -l
# install specified version
protocenv install <version>
# set global version
protocenv global <version>
# set local version
protocenv local <version>