Use bufio.ReadString to read user input.

[Tonkpils]

fmt.Scanln treates spaces as a discontinuation of input according to http://golang.org/pkg/fmt/#Scanln

Fixes #65

[Tonkpils]

@kytrinyx I also noticed that the error set when failing to make the directory is not being displayed.

https://github.com/exercism/cli/blob/master/exercism.go#L57-L60

Not sure if you wanted to handle this with a panic or just display a message to the user. So I didn't make a commit for it yet.

[kytrinyx]

Thank you for this!

I don't really know what the idiomatic approach is, which is why there's no consistent approach right now. What do you think? Just panic?

[Tonkpils]

I'm actually not sure either 😊

I think that a nicely formatted message to the user might cause a bit less panic 😄. I'm wondering if, apart from the message, the creation of the configuration file should fail or if it should just succeed and let the user know to make sure that the directory is created before proceeding to use the other commands.

Currently, it creates the file but it does it with empty values for each of the attributes.

[kytrinyx]

Hm. Good points, all. I think you're right that a friendly message would be better. Also, I think it should fail to create the config file.

[Tonkpils]

Sounds good! I'll get working on that.