fix presumably busted unemptyString

[boneskull]

Hi,

I wanted to assert that a function was passed an unempty string, so I wrote something like the following:

import is from 'check-more-types';

function myFunc (value) {
  is.verify.unemptyString(value);
}

myFunc('');

I found that this did not throw an exception. Upon further investigation, verify only throws when the result of a comparison is strictly false. I modified unemptyString() to ensure it always returns a boolean value.

To assert my changes worked, I attempted to run npm test. However, the unit tests were not executed--not sure why. I enabled them as part of this PR. If you would like me to disable them again, I can remove 398a986.

[bahmutov]

Ohhh, this is such a sweet bug and great fix! I am honestly not using check.verify - only using lazy-ass with checks. I will publish new version after merging with my local code tests shortly.

Huge thank you!

[bahmutov]

published as v2.12.0