add troubleshooting in contributing section
When I ran the test suite on macOSX, I had some issues regarding SSL configuration, I have documented the error I encounter and the solution to deal with it.
@@ -23,3 +23,24 @@ documentation <https://boto.readthedocs.io/en/latest/getting_started.html>`__
for how to set this up. I have marked the boto tests as optional in
Travis so you don't have to worry about them failing if you submit a
pull request.
+
+
+Troubleshooting on MacOSX
+-------------------------
+
+If you have this kind of error when running tox :
+
+.. code:: python
+
+ __main__.ConfigurationError: Curl is configured to use SSL, but we have
+ not been able to determine which SSL backend it is using. Please see PycURL documentation for how to specify the SSL backend manually.
+
+Then you need to define some environment variables:
+
+.. code:: bash
+
+ export PYCURL_SSL_LIBRARY=openssl
+ export LDFLAGS=-L/usr/local/opt/openssl/lib
+ export CPPFLAGS=-I/usr/local/opt/openssl/include
+
+Reference : `stackoverflow issue <https://stackoverflow.com/questions/51019622/curl-is-configured-to-use-ssl-but-we-have-not-been-able-to-determine-which-ssl>`__
