Added support for .NET 4.5

Author: Lachee

DiscordRPC/DiscordRPC.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net45</TargetFrameworks>
     <NuspecFile>DiscordRPC.nuspec</NuspecFile>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>

DiscordRPC/DiscordRPC.nuspec

@@ -18,21 +18,27 @@ This is an unoffical, non-discord supported library.
     <license type="expression">MIT</license>
     <projectUrl>https://github.com/Lachee/discord-rpc-csharp</projectUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
-    <copyright>Copyright (c) Lachee 2018</copyright>
     <releaseNotes></releaseNotes>
     <tags>Discord Discord Rich Presence RPC Discord-RPC</tags>
 
     <dependencies>
       <group targetFramework="netstandard2.0">
-        <dependency id="Newtonsoft.Json" version="12.0.2" />
+        <dependency id="Newtonsoft.Json" version="13.0.1" />
         <dependency id="Microsoft.Win32.Registry" version="4.5.0" />
       </group>
+      <group targetFramework="net45">
+        <dependency id="Newtonsoft.Json" version="13.0.1" />
+      </group>
     </dependencies>
   </metadata>
 
   <files>
     <file src="./bin/Release/netstandard2.0/DiscordRPC.dll" target="lib\netstandard2.0" />
     <file src="./bin/Release/netstandard2.0/DiscordRPC.pdb" target="lib\netstandard2.0" />
     <file src="./bin/Release/netstandard2.0/DiscordRPC.xml" target="lib\netstandard2.0" />
+	
+	<file src="./bin/Release/net45/DiscordRPC.dll" target="lib\net45" />
+    <file src="./bin/Release/net45/DiscordRPC.pdb" target="lib\net45" />
+    <file src="./bin/Release/net45/DiscordRPC.xml" target="lib\net45" />
   </files>
 </package>