Update license year from 2014 to range '2014-2016'

[fluxw42]

How to use GNU licenses for your own software (Most parts also apply to the MIT license)

The copyright notice should include the year in which you finished preparing the release (so if you finished it in 1998 but didn't post it until 1999, use 1998). You should add the proper year for each release; for example, “Copyright 1998, 1999 Terry Jones” if some versions were finished in 1998 and some were finished in 1999.
...
For software with several releases over multiple years, it's okay to use a range (“2008-2010”) instead of listing individual years (“2008, 2009, 2010”) if and only if every year in the range, inclusive, really is a “copyrightable” year that would be listed individually; and you make an explicit statement in your documentation about this usage.

There was definitely copyrightable activity on all years:
git log --format="%ad" --date="iso" | cut -c -4 | sort | uniq

So this pull requests updates the year '2014' in LICENSE.md to a range '2014-2016

[iluwatar]

You are correct @fluxw42 Thanks for the fix!

[iluwatar]

@all-contributors please add @fluxw42 for code

[allcontributors]

@iluwatar

I've put up a pull request to add @fluxw42! 🎉