Add section test data.

docs/source/testing.rst

-Testing
-*******
+Test reproducibility
+********************
 
 The `test` directory contains tests which can ensure that updates to
-notebooks and libraries do not result in unintended changes to
+correction notebooks and libraries do not result in unintended changes to
 notebook output. This assures consistency of correction results
 for subsequent versions.
 
@@ -98,3 +98,20 @@ directory.
     `test_rsts subfolder` of this documentation. Also, do not commit
     `test_results.rst`. It is autogenerated.
 
+Test Data
++++++++++
+
+In order to perform described test a detector data as well as calibration constants are required. These for AGIPD and LDP can be found in::
+
+    /gpfs/exfel/exp/XMPL/201750/p700001/raw/
+
+A common place to locate output of tests is::
+
+    /gpfs/exfel/exp/XMPL/201750/p700001/scratch/
+
+Calibration constants to perform test are here::
+
+    /gpfs/exfel/exp/XMPL/201750/p700001/usr
+
+.. include:: test_results.rst
+