Add support for explicit 0 and 1 rules in #depluralize_key.

lib/i18n/tasks/plural_keys.rb

@@ -56,6 +56,6 @@ def plural_forms?(s)
   end
 
   def plural_suffix?(key)
-    PLURAL_KEY_SUFFIXES.include?(key)
+    PLURAL_KEY_SUFFIXES.include?(key) || %w[0 1].include?(key)
   end
 end

spec/plural_keys_spec.rb

@@ -31,6 +31,12 @@
         plural_key: {
           other: '%{count}'
         }
+      },
+
+      explicit_0_1_rules: {
+        '0': 'zero',
+        '1': 'one',
+        other: '%{count}'
       }
     }
   end
@@ -62,6 +68,15 @@
       expect(depluralize('not_really_plural.one')).to eq('not_really_plural.one')
     end
 
+    it 'does not ignore `0` and `1` explicit rules' do
+      expect(depluralize('explicit_0_1_rules.0')).to eq('explicit_0_1_rules.0')
+      expect(depluralize('explicit_0_1_rules.1')).to eq('explicit_0_1_rules.1')
+    end
+
+    it 'depluralizes keys that have explicit `0` and `1` rules siblings' do
+      expect(depluralize('explicit_0_1_rules.other')).to eq('explicit_0_1_rules')
+    end
+
     def depluralize(key)
       task.depluralize_key(key, 'en')
     end