Make this run in check mode

[sr]

The role fails when it runs with ansible-playbook --check:

TASK: [joshualund.golang | Extract the Go tarball if Go is not yet installed or if it is not the desired version] *
**
fatal: [146.148.4.191] => error while evaluating conditional: not go_version|skipped and go_version|failed or go_ve
rsion.stdout != go_version_target

FATAL: all hosts have already failed -- aborting

This is because in check mode ansible doesn't execute commands and instead returns an object with a skipped attribute set to true.