Add exceptional case for isDate

[KisukPark]

@chriso

Hi, I just found that isDate() returns false with '2016-02-20T16:23:48.5'

It is because...
dayOrYearMatches = str.match(/(^|[^:\d])[23]\d([^:\d]|$)/g);
matches '-20T' and fails.

There was similar case '2010-02-18T16:23:48.5'
In this case, the regex matches nothing.

So, I add T in the regex to match nth for the exceptional case.
dayOrYearMatches = str.match(/(^|[^:\d])[23]\d([^T:\d]|$)/g);

Please feedback me whether I did right or not.
Thanks.

• Kisuk

[coveralls]

Coverage remained the same at 99.103% when pulling ff4a713 on KisukPark:isdate-exceptional into a8b3eba on chriso:master.

[KisukPark]

There was an build fail when exec babel-node build-browser && npm run minify which is not related with my changes.
Please check.

Thanks.

[chriso]

Thanks. The Travis errors have been fixed in master.

[KisukPark]

Thanks!!