software/end-to-end-testing: Add README.md

software/end-to-end-testing/README.md

+# End To End Testing
+
+This software release is used to run end-to-end test of SlapOS softwares on an actual SlapOS cloud such as Rapid.Space. Since it can supply softwares and request instances on an actual cloud, it needs a SlaPOS client certificate.
+
+Input parameters:
+
+```
+{
+  "client.crt": <content of client.crt>
+  "client.key": <content of client.key>
+  "master-url": <url of SlapOS master>
+}
+```
+
+A convenience script `generate_parameters.py` is provided to compute these parameters in JSON format from an existing SlapOS client configuration:
+
+```
+python3 generate_parameters.py --cfg <path to slapos-client.cfg> -o <output path>
+```