Update ImageSharp to 1.0.4

Author: brianpopow

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -21,7 +21,7 @@
 
   <ItemGroup>
     <PackageReference Include="SixLabors.Fonts" Version="1.0.0-beta15.15" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.3" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.4" />
   </ItemGroup>
 
   <Import Project="..\..\shared-infrastructure\src\SharedInfrastructure\SharedInfrastructure.projitems" Label="Shared" />