[fixed] Can't close Modal B on examples

[FullMoon04]

Fixes #725.

Changes proposed:

• can close modal B with close button

Acceptance Checklist:

• The commit message follows the guidelines in CONTRIBUTING.md.
• Documentation (README.md) and examples have been updated as needed.
• If this is a code change, a spec testing the functionality has been added.
• If the commit message has [changed] or [removed], there is an upgrade path above.

[coveralls]

Coverage remained the same at 86.56% when pulling 27b30ac on FullMoon04:fix/examples into d4a8a32 on reactjs:master.

[FullMoon04]

I noticed now that I can close a modal with esc.
However, I think it would be better to have a button to close the modal B.

[rocifier]

I think this should be merged, it actually fixes the issue.

[diasbruno]

Oh, sorry for the delay on this one. I'll merge this.

Thanks @FullMoon04 and @rocifier.