Update metedata and CHANGELOG for v1.0.3 release

CHANGELOG

+* Wed Feb 04 2015 Stefan Schulte <stefan.schulte@taunusstein.net> 1.0.3
+- do not crash on unexpected rpm output
+- improve test coverage
 * Sat Feb 01 2015 Stefan Schulte <stefan.schulte@taunusstein.net> 1.0.2
 - Add SLES and CentOS as supported operating systems (thanks to Michael Moll
   and Gene Liverman for testing)

metadata.json

 {
   "name": "stschulte-rpmkey",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "author": "stschulte",
   "summary": "Manage your RPM keyring through puppet",
   "license": "Apache-2.0",