fix: Fixed nuget binary inclusion by using UNIX path

Author: TwoTenPvP

Ruffles.nuspec

@@ -22,10 +22,10 @@
   </metadata>
   <files>
     <file src="LICENCE" target="LICENCE" />
-	  <file src="Ruffles\bin\$configuration$\net35\**" target="lib\net35"/>
-    <file src="Ruffles\bin\$configuration$\net45\**" target="lib\net45"/>
-    <file src="Ruffles\bin\$configuration$\net471\**" target="lib\net471"/>
-	  <file src="Ruffles\bin\$configuration$\netcoreapp2.0\**" target="lib\netcoreapp2.0"/>
-	  <file src="Ruffles\bin\$configuration$\netstandard2.0\**" target="lib\netstandard2.0"/>
+	  <file src="Ruffles/bin/$configuration$/net35/**" target="lib/net35/**"/>
+    <file src="Ruffles/bin/$configuration$/net45/**" target="lib/net45/**"/>
+    <file src="Ruffles/bin/$configuration$/net471/**" target="lib/net471/**"/>
+	  <file src="Ruffles/bin/$configuration$/netcoreapp2.0/**" target="lib/netcoreapp2.0/**"/>
+	  <file src="Ruffles/bin/$configuration$/netstandard2.0/**" target="lib/netstandard2.0/**"/>
   </files>
 </package>