Headings cannot be parsed from localized abbreviations

[hangy]

[Fact]
[UseCulture("da")]
public void CanParseLocalizedAbbreviation()
{
    const double heading = 22.5;
    var abbreviation = heading.ToHeading();

    var actual = abbreviation.FromAbbreviatedHeading();

    Assert.Equal(heading, actual);
}

This test fails as of 5c3b134, because FromAbbreviatedHeading only ever looks up the abbreviated heading in the English base array:

Humanizer/src/Humanizer/HeadingExtensions.cs

Line 76 in 12cc400

var index = Array.IndexOf(headings, heading.ToUpperInvariant());

The translated value "NNØ" is not used. The test works well for the en locale.