[5.0] Added A Space After Questions

Issuing this pull request to the master branch as requested by @taylorotwell 

This pull request relates to the Command class.

The commit here adds a space after a question so the input is more readable. This could have been missed as the `confirm()` method has a space in it to separate the input.

To clarify:

Running `$this->ask('What is your name?');`

Output before:
`What is your name?`input

Output now:
`What is your name?` input