Remove useless regular-expression character escape

[smorimoto]

This PR fixes the problem found by #358 (though it's hardly a problem).

[coveralls]

Coverage remained the same at 100.0% when pulling 8a1e162 on smorimoto:remove-useless-regex-char-escape into 093b40f on npm:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 8a1e162 on smorimoto:remove-useless-regex-char-escape into 093b40f on npm:master.

[lukekarrys]

The escape is useless, but the fix should be to add another \ so the resulting regex only matches a literal . and not any character. I implemented this in #432.

[smorimoto]

@lukekarrys Brilliant!