Add release notes for 1.5.2

Author: odinserj

nuspecs/Hangfire.Core.nuspec

@@ -14,8 +14,11 @@
     <tags>Hangfire OWIN Long-Running Background Fire-And-Forget Delayed Recurring Tasks Jobs Scheduler Threading Queues</tags>
     <releaseNotes>http://hangfire.io/blog/
 
+1.5.2
+* Fixed – `JobLoadException` when using interface method as a background job, appeared in 1.5.1.
+    
 1.5.1
-* Fixed – `JobLoadException` during deserialization when a method defined in an inherited interface (by @triwire).
+* Fixed – `JobLoadException` during deserialization when a method defined in an inherited interface.
 * Fixed – Show alert box instead of an exception on Awaiting Jobs page.
 
 1.5.0

nuspecs/Hangfire.nuspec

@@ -18,8 +18,11 @@
     <tags>Hangfire AspNet MVC OWIN SqlServer Long-Running Background Fire-And-Forget Delayed Recurring Tasks Jobs Scheduler Threading Queues</tags>
     <releaseNotes>http://hangfire.io/blog/
 
+1.5.2
+* Fixed – `JobLoadException` when using interface method as a background job, appeared in 1.5.1.
+    
 1.5.1
-* Fixed – `JobLoadException` during deserialization when a method defined in an inherited interface (by @triwire).
+* Fixed – `JobLoadException` during deserialization when a method defined in an inherited interface.
 * Fixed – Unable to see enqueued jobs in Dashboard UI when using SQL Server queues.
 * Fixed – Show alert box instead of an exception on Awaiting Jobs page.