Update language-to-model matcher to handle 5-letter languages
Update language-to-model matcher to handle 5-letter languages

The Identifiable languages API recently changed to returning 5-letter languages/locales while the list of LT models still returns only 2-letter languages. Because of this, a direct comparison always fails.

The new change still attempts a direct comparison for best accuracy, but falls back to a language-only match to enable 2-letter to 5-letter comparisons.
watson-developer-cloud/language-translation-nodejs,watson-developer-cloud/language-translation-nodejs