added SECUTRITY.md for reporting vulnerabilities (#805)

SECURITY.md

@@ -0,0 +1,25 @@
+# Security Policy
+
+## Supported Versions
+
+As announced in the [README](README.md) I only support the latest available release and master.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| master  | :white_check_mark: |
+| 0.9     | :white_check_mark: |
+| < 0.9   | :x:                |
+
+## Reporting a Vulnerability
+
+Please report any security related vulnerability to info@keleo.de or kpapst@gmx.net.
+
+I will work as fast as I can to fix the problem and publish a bugfix release. 
+Depending on the size of the required fixes, this might take between a couple of hours up 
+to a couple of days.
+
+You can expect that your message (via email is the preferred way) will be answered ASAP, 
+but please take into account that I am living in the timezone Europe/Berlin. 
+
+If your issue is valid and I verified and fixed it, you will be mentioned in the release 
+notes within the Security section at the top of the release.