agate: Inappropriate cast to timestamp

Created by: fgregg

csvkit==1.0.2, ubuntu

the following one column csv is miscast to timestamps:

foo
720(38-4)31A-1.1(A)

> printf "foo\n720(38-4)31A-1.1(A)" | csvlook
|                 foo |
| ------------------- |
| 2040-01-01 07:20:00 |