DOC: Added a small "Getting started" into README.md.

README.md

@@ -5,6 +5,15 @@
 This is the **CaosDB Python Integration Tests** repository and a part of the
 CaosDB project.
 
+# Getting started #
+
+To run tests, start up a CaosDB server (documentation for this can be found
+elsewhere). Then modify `pycaosdb.ini.template` accordingly and save it as
+`pycaosdb.ini`.  Then you can run the tests with `pytest` or `pytest-3`
+(depending on your system).
+
+If you want to run just a single test, you can also select a single test file:
+`pytest-3 tests/test_issues.py`
 
 # Further Reading