Now that we require Ruby over `2.3`, we can replace the current
suggestion methods we have with tooling from the `did_you_mean` gem.
There is a small user visible change and this is that we now offer a
single suggestion for misspelled options. We are suggesting fixes during
generator invocation and during a mistyped rails server rack handler. In
both cases, if we don't make a proper prediction on the first match, we
won't do so in the second or third one, so in my mind, this is okay.
When secrets confirmed with the `secrets:edit` command, `secrets.yml.enc`
will change without updating the secrets.
Therefore, even if only want to check secrets, the difference will come
out. This is a little inconvenient.
In order to solve this problem, added the `secrets:show` command.
If just want to check secrets, no difference will occur use this command.
