replaced iconurl with icon tag. added icon file

Author: mano-si

nuget/deprecated/nunit.engine.netstandard.nuspec

@@ -9,8 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>Deprecated NUnit 3 .NET Standard engine - use NUnit.Engine.</summary>
     <description>
@@ -29,5 +28,6 @@
   </metadata>
   <files>
     <file src="LICENSE.txt" />
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>

nuget/deprecated/nunit.runners.nuspec

@@ -9,7 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>Deprecated NUnit 3 console runner - use NUnit.Console or NUnit.ConsoleRunner.</summary>
     <description>
@@ -38,5 +38,6 @@
   </metadata>
   <files>
     <file src="LICENSE.txt" />
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>

nuget/engine/nunit.engine.api.nuspec

@@ -9,7 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>The NUnit Test Engine Api is used by runners to interface with the NUnit Engine in order to discover and execute tests.</summary>
     <description>This package includes the nunit.engine.api, which is normally the only assembly referenced by runners as well as by engine extensions. It is not intended for direct use by users who simply want to run tests using NUnit.</description>
@@ -34,5 +34,6 @@
     <file src="bin/net20/nunit.engine.api.dll" target="lib/net20" />
     <file src="bin/netstandard1.6/nunit.engine.api.dll" target="lib/netstandard1.6" />
     <file src="bin/netstandard2.0/nunit.engine.api.dll" target="lib/netstandard2.0" />
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>

nuget/engine/nunit.engine.nuspec

@@ -9,7 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>The NUnit Test Engine is used by runners to discover and execute tests.</summary>
     <description>This package includes nunit.engine and related assemblies, for use by runner programs. It is not intended for direct use by users who simply want to run tests.</description>
@@ -64,5 +64,6 @@
     <file src="bin/netstandard2.0/Mono.Cecil.dll" target="lib/netstandard2.0" />
     <file src="../../nuget/engine/nunit.engine.nuget.addins" target="contentFiles/any/netstandard2.0"/>
     <file src="..\..\nuget\engine\build\**\*" target="build" />
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>

nuget/runners/nunit.console-runner-with-extensions.nuspec

@@ -9,7 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>Console runner for the NUnit 3 unit-testing framework with selected extensions.</summary>
     <description>
@@ -41,5 +41,6 @@
   </metadata>
   <files>
     <file src="LICENSE.txt" />
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>

nuget/runners/nunit.console-runner.nuspec

@@ -9,7 +9,7 @@
     <license type="file">LICENSE.txt</license>
     <projectUrl>https://nunit.org</projectUrl>
     <repository type="git" url="https://github.com/nunit/nunit-console"/>
-    <iconUrl>https://cdn.rawgit.com/nunit/resources/master/images/icon/nunit_256.png</iconUrl>
+    <icon>images\icon_256.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <summary>Console runner for the NUnit 3 unit-testing framework, without any extensions.</summary>
     <description>
@@ -38,5 +38,6 @@
     <file src="bin/net20/nunit.engine.dll" target="tools" />
     <file src="bin/net20/Mono.Cecil.dll" target="tools" />
     <file src="..\..\nuget\runners\nunit.console.nuget.addins" target="tools"/>
+    <file src="icon_256.png" target="images\" />
   </files>
 </package>