Review fixes for 'Created metric class'

- Changed metric to_json to dumpConfiguration returning LabeledTuple
- LabeledTuple can be created and assigned directly to json
- LabeledTuple can be readed from json using json.get<LabeledTuple>
- Added PrintTo for LabeledMetricParams, LabeledSensorParams
- Added helper method expectMake to ReportFactoryMock
- sensorPaths are serialized to tuple<service, path> instead of single
  field with service and path separated via ':'
- Changed configuration version from 1 to 2

Change-Id: I7c45fb584687172f88fd549a93329264793b0b8e
Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
diff --git a/tests/src/test_transform.cpp b/tests/src/test_transform.cpp
index c97cf5f..66fa855 100644
--- a/tests/src/test_transform.cpp
+++ b/tests/src/test_transform.cpp
@@ -1,3 +1,4 @@
+#include "helpers.hpp"
 #include "utils/transform.hpp"
 
 #include <set>