Update assembly info file for v1.0.3-preview001 [skip ci]

[version update]

Author: nfbot

source/nanoFramework.CoreLibrary/System/AssemblyInfo2.cs

@@ -13,6 +13,6 @@
 [assembly: AssemblyProduct("nanoFramework mscorlib")]
 [assembly: AssemblyCopyright("Copyright © nanoFramework Contributors 2017")]
 
-[assembly: AssemblyVersion("1.0.2.0")]
-[assembly: AssemblyFileVersion("1.0.2.0")]
-[assembly: AssemblyInformationalVersion("1.0.2-rc001")]
+[assembly: AssemblyVersion("1.0.3.0")]
+[assembly: AssemblyFileVersion("1.0.3.0")]
+[assembly: AssemblyInformationalVersion("1.0.3-preview001")]