Fix PLURAL operator when less params are specified

The behaviour was previously incorrect for cases where the language has no plural rule defined (such as English, Chinese, etc) and the number isn't 1.

such as `new Banana('en').i18n('{{PLURAL:$1|foo}}', 3)` which was giving `undefined` instead of `foo`.

This bug isn't affecting `banana-i18n` because it uses Intl so this code path isn't there.

src/languages/language.js

@@ -40,7 +40,7 @@ export default class BananaLanguage {
 
     if (!pluralRules) {
       // default fallback.
-      return (count === 1) ? forms[ 0 ] : forms[ 1 ]
+      pluralRules = { one: 'i = 1 and v = 0' }
     }
 
     let pluralFormIndex = this.getPluralForm(count, pluralRules)

test/banana.test.js

@@ -487,8 +487,6 @@ describe('Banana', function () {
   it('should parse the plural and gender', () => {
     let locale = 'en'
     const banana = new Banana(locale, {})
-    const messages = fs.readFileSync(`./test/i18n/${locale}.json`)
-    banana.load(JSON.parse(messages), locale)
     assert.strictEqual(
       banana.i18n('This message key does not exist'),
       'This message key does not exist',
@@ -527,7 +525,12 @@ describe('Banana', function () {
     assert.strictEqual(
       banana.i18n(pluralAndGenderMessageWithLessParaMS, 'Meera', 1, 'female'),
       'Meera has 1 kitten. She loves to play with it.',
-      'Plural and gender test - female, singular, but will less parameters in message'
+      'Plural and gender test - female, singular, but with less parameters in message'
+    )
+    assert.strictEqual(
+      banana.i18n(pluralAndGenderMessageWithLessParaMS, 'Meera', 2, 'female'),
+      'Meera has 2 kitten. She loves to play with it.',
+      'Plural and gender test - female, plural, with less parameters in message'
     )
     assert.strictEqual(
       banana.i18n(pluralAndGenderMessageWithCase, 'Meera', 1, 'female'),