Updating contribution to aid debugging (#961)

* Updating contribution to aid debugging

* More explicit instructions

Author: Neeratyoy

CONTRIBUTING.md

@@ -239,6 +239,11 @@ You may then run a specific module, test case, or unit test respectively:
   $ pytest tests/test_datasets/test_dataset.py::OpenMLDatasetTest::test_get_data
 ```
 
+*NOTE*: In the case the examples build fails during the Continuous Integration test online, please 
+fix the first failing example. If the first failing example switched the server from live to test 
+or vice-versa, and the subsequent examples expect the other server, the ensuing examples will fail 
+to be built as well.
+
 Happy testing!
 
 Documentation

doc/contributing.rst

@@ -18,12 +18,10 @@ In particular, a few ways to contribute to openml-python are:
    are hosted in separate repositories and may have their own guidelines.
    For more information, see the :ref:`extensions` below.
 
- * Bug reports. If something doesn't work for you or is cumbersome, please
-  open a new issue to let us know about the problem.
-  See `this section <https://github.com/openml/openml-python/blob/develop/CONTRIBUTING.md#reporting-bugs>`_.
+ * Bug reports. If something doesn't work for you or is cumbersome, please open a new issue to let
+   us know about the problem. See `this section <https://github.com/openml/openml-python/blob/develop/CONTRIBUTING.md#reporting-bugs>`_.
 
- * `Cite OpenML <https://www.openml.org/cite>`_ if you use it in a scientific
-  publication.
+ * `Cite OpenML <https://www.openml.org/cite>`_ if you use it in a scientific publication.
 
  * Visit one of our `hackathons <https://meet.openml.org/>`_.