Add net461 target framework for NEST.JsonNetSerializer

This commit adds a specific net461 TFM into the NEST.JsonNetSerializer package. This TFM is already being built in the project.

Author: russcam

build/NEST.JsonNetSerializer.nuspec

@@ -16,6 +16,10 @@
 		<copyright>2017-$year$ Elasticsearch BV</copyright>
 		<tags>elasticsearch,elastic,search,lucene,nest,serializer,json</tags>
 		<dependencies>
+			<group targetFramework="net461">
+				<dependency id="NEST" version="[$version$, $nextMajorVersion$)" />
+				<dependency id="Newtonsoft.Json" version="$jsonDotNetCurrentVersion$" />
+			</group>
 			<group targetFramework="netstandard2.0">
 				<dependency id="NEST" version="[$version$, $nextMajorVersion$)" />
 				<dependency id="Newtonsoft.Json" version="$jsonDotNetCurrentVersion$" />
@@ -24,6 +28,9 @@
 	</metadata>
 	<files>
 		<file src="..\license.txt" target="" />
+
+		<file src="output\Nest.JsonNetSerializer\net461\Nest.JsonNetSerializer.dll" target="lib\net461"/>
+		<file src="output\Nest.JsonNetSerializer\net461\Nest.JsonNetSerializer.xml" target="lib\net461"/>
 
 		<file src="output\Nest.JsonNetSerializer\netstandard2.0\Nest.JsonNetSerializer.dll" target="lib\netstandard2.0"/>
 		<file src="output\Nest.JsonNetSerializer\netstandard2.0\Nest.JsonNetSerializer.xml" target="lib\netstandard2.0"/>