Update SECURITY.md

Author: stefannibrasil

SECURITY.md

@@ -1,4 +1,12 @@
-## Security and Vulnerability Reporting
+## Security Policy
+
+### Supported Versions
+
+Only the the latest version of this project is supported at a given time. If you find a security issue with an older version, please try updating to the latest version first.
+
+If for some reason you can't update to the latest version, please let us know your reasons so that we can have a better understanding of your situation.
+
+## Reporting a Vulnerability
 
 The faker-ruby core contributors take security very seriously and investigate all reported vulnerabilities.