* added tests for new signature
- kept all the original tests.
Tagged the tests to remove after signature change is complete.
- leveraged a test from test_cyctoscape.py, checks for warnings.
- made new versions of tests that use attrs in the signature.
* Verified that the new tests fail. Good.
* update signatures with keywords
* added warning message
* adapted code to use keywords
* move test with recwarn fixture outside of class
when recwarn was used in a method, got an error.
work fine in a function.
* add warning to node_link_graph()
* update node_link_graph() to use keywords
* use recwarn in test to dectect warnings
* added deprecation notices to doc strings.
Needs version number for when deprecation will happen
* added example code from doc string to tests
* gave default values to elements of attrs
the example code passes a dict with only some of the keywords defined.
So the defaults needed to be provided
* fixed name conflict
* brace in docstring
* drop braces in doc string example
* Changed namespace to nx in doc string examples
* update the examples
- show the results of the examples
- add more examples of serialization with json
* Update doc desc and notes
- Add reference to Serialization in the method description.
- add a note that the keywords chose for the attributes names must match
if the two functions are to be used together
* clean up wording
* document the version numbers for deprecating
deprecate the change in 2.8.6
remove the change in 3.1
* Add note, on using old and new keywords together
* Add Deprecation Warning to conftest.py
* Add a reminder to remove code & docs in 3.1