Allow for ignoring closing "/>" position when jsx-alignment is enabled

[bolatovumar]

Would you consider merging in a PR which adds a rule option for ignoring the position of the closing "/>" ?

I'm asking because I would like to get the main benefit of this rule (only one JSX element per line) without having to worry about where the closing "/>" is located. I will implement this if it's something you would be OK with merging.

[adidahiya]

closing in favor of #100