Add this to jupyter_notebook_config.py in order to auto remove cell numbers and output from jupyter notebooks.

jupyter_remove_nums_and_output.py

def scrub_output_pre_save(model, **kwargs):
    """scrub output before saving notebooks"""
    # only run on notebooks
    if model['type'] != 'notebook':
        return
    # only run on nbformat v4
    if model['content']['nbformat'] != 4:
        return

    for cell in model['content']['cells']:
        if cell['cell_type'] != 'code':
            continue
        cell['outputs'] = []
        cell['execution_count'] = None

c.FileContentsManager.pre_save_hook = scrub_output_pre_save

To show config directory:
$ jupyter --config-dir

To create a config file if one doesn't already exist:
$ jupyter notebook --generate-config