Update version information

Build/MQTTnet.nuspec

@@ -2,7 +2,7 @@
 <package >
   <metadata>
     <id>MQTTnet</id>
-    <version>2.4.0</version>
+    <version>2.5.0</version>
     <authors>Christian Kratky</authors>
     <owners>Christian Kratky</owners>
     <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
@@ -10,17 +10,7 @@
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>MQTTnet is a .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
-    <releaseNotes>* [Server] Added an event which is fired when a client has disconnected
-* [Server] Added support for retained application messages
-* [Server] Added support for saving and loading retained messages
-* [Server] The client connection is now closed if sending of one pending application message has failed
-* [Server] Fixed handling of _Dup_ flag (Thanks to haeberle)
-* [Core] Optimized exception handling
-* [Core] Mono is now also supported (Thanks to JTrotta)
-* [Client] The options are now passed in _ConnectAsync_ (Breaking change! Read Wiki for examples)
-* [Core] Trace class renamed to _MqttNetTrace_ (Breaking change!)
-* [Client] Extended certificate validation options (Breaking change!)
-* [Client] Added static certificate validation callback (NetFramework, NetStandard) / ignorable certificate errors (UniversalWindows) to _MqttTcpChannel_
+    <releaseNotes>* [Core] Merged the .NET Framwork and netstandard projects (Thanks to @JanEggers)
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2017</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M</tags>