Update readme for the release v0.3

Author: shauheen

README.md

@@ -18,7 +18,7 @@ Along with these ML capabilities this first release of ML.NET also brings the fi
 
 ML.NET runs on Windows, Linux, and macOS - any platform where 64 bit [.NET Core](https://github.com/dotnet/core) or later is available.
 
-The current release is 0.2. Check out the [release notes](docs/release-notes/0.2/release-0.2.md).
+The current release is 0.3. Check out the [release notes](docs/release-notes/0.3/release-0.3.md).
 
 First ensure you have installed [.NET Core 2.0](https://www.microsoft.com/net/learn/get-started) or later. ML.NET also works on the .NET Framework. Note that ML.NET currently must run in a 64 bit process.