Added Swedish collection formatter

src/Humanizer.Tests.Shared/Humanizer.Tests.Shared.projitems

@@ -127,6 +127,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\sr\DateHumanizeTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\sr\NumberToWordsTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\sr\TimeSpanHumanizeTests.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Localisation\sv\CollectionFormatterTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\sv\DateHumanizeTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\sv\TimeSpanHumanizeTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Localisation\tr\DateHumanizeTests.cs" />

src/Humanizer.Tests.Shared/Localisation/sv/CollectionFormatterTests.cs

@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+using Xunit;
+
+namespace Humanizer.Tests.Localisation.sv
+{
+    [UseCulture("sv-SE")]
+    public class CollectionFormatterTests
+    {
+        [Fact]
+        public void MoreThanTwoItems()
+        {
+            var collection = new List<int>(new[] {1, 2, 3});
+            var humanized = "1, 2 och 3";
+            Assert.Equal(humanized, collection.Humanize());
+        }
+
+        [Fact]
+        public void OneItem()
+        {
+            var collection = new List<int>(new[] {1});
+            var humanized = "1";
+            Assert.Equal(humanized, collection.Humanize());
+        }
+
+        [Fact]
+        public void TwoItems()
+        {
+            var collection = new List<int>(new[] {1, 2});
+            var humanized = "1 och 2";
+            Assert.Equal(humanized, collection.Humanize());
+        }
+    }
+}

src/Humanizer/Configuration/CollectionFormatterRegistry.cs

@@ -16,6 +16,7 @@ public CollectionFormatterRegistry()
             Register("ro", new DefaultCollectionFormatter("și"));
             Register("nn", new DefaultCollectionFormatter("og"));
             Register("nb", new DefaultCollectionFormatter("og"));
+            Register("sv", new DefaultCollectionFormatter("och"));
         }
     }
 }