More informative failure when passing bytes to a Unicode traitlet
Fall back to default editor if $EDITOR is non-ASCII.

Closes gh-4615
Merge pull request #4624 from takluyver/i4615

Fix crash when $EDITOR is non-ASCII

closes #4615
Restore the ability to run tests from a function.
Allow any options to be passed through test function
add example of likely kwargs to test() docstring
Merge pull request #9 from ivanov/testfunc

added a doc string example
Fix docstring codeblock
Merge pull request #4632 from takluyver/testfunc

Restore the ability to run tests from a function.
Fix nbrun in notebooks with non-code cells.
Added a text cell in the notebook to test run_nb.
Merge pull request #4634 from damianavila/fix_nbrun

Fix nbrun in notebooks with non-code cells.