Date `12/31/17` incorrectly given format of `YYYY/M/D`

[matthias-ccri]

A date string like 12/31/17 is incorrectly given the YYYY/M/D format, whereas it should be M/D/YYYY.

It looks like there are unit tests that try to cover this:

type-analyzer/test/time-test.js

Lines 48 to 52 in 617c783

	arr = ['1/1/15', '11/2/98', '1/31/00', '12/31/17'].map(mapArr);
	result = Analyzer.computeColMeta(arr)[0];
	assert.deepEqual({type: result.type, format: result.format},
	{type: 'DATE', format: 'M/D/YYYY'},
	'Inteprets dates formatted as M/D/YYYY correctly');

but not all of the dates are actually tested. If you change the order of the dates and make 12/31/17 first, the test fails.