Fix package id (#60)

Author: VisualMelon

Source/OxyPlot.Avalonia/OxyPlot.Avalonia.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <PackageId>AvaloniaOU.Oxyplot</PackageId>
+    <PackageId>Oxyplot.Avalonia</PackageId>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
     <Description>OxyPlot is a plotting library for .NET. This is a support library for OxyPlot to work with AvaloniaUI.</Description>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

Source/OxyPlot.Avalonia/PlotBase.cs

@@ -16,7 +16,6 @@ namespace OxyPlot.Avalonia
     using global::Avalonia.Controls.Presenters;
     using global::Avalonia.Controls.Primitives;
     using global::Avalonia.Input;
-    using global::Avalonia.Input.Platform;
     using global::Avalonia.Threading;
     using global::Avalonia.VisualTree;
     using System;