nbconvert json decoding error

I believe this error might be related to #8009. I've managed to get the hooks in #8009 to work (somewhat) producing desired `.py` and `.html` files after a checkpoint. However, I am getting a `ValueError: No JSON object could be decoded` having to do with my nb config `.json` file that I don't really understand. Any ideas what I am doing wrong here?

`sys.info` returns:

> {'commit_hash': u'5a894b9',
> 'commit_source': 'installation',
> 'default_encoding': 'UTF-8',
> 'ipython_path': '/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/site-packages/IPython',
> 'ipython_version': '5.3.0',
> 'os_name': 'posix',
> 'platform': 'Linux-4.4.0-96-generic-x86_64-with-debian-stretch-sid',
> 'sys_executable': '/home/ktavabi/miniconda3/envs/andrea-anders/bin/python',
> 'sys_platform': 'linux2',
> 'sys_version': '2.7.13 |Continuum Analytics, Inc.| (default, Dec 20 2016, 23:09:15) \n[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)]'}

I am working in a conda virtual env with following packages:

> jupyter 1.0.0
> jupyter_client 5.1.0
> jupyter_console 5.1.0
> jupyter_core 4.3.0
> nbconvert 5.2.1
> nbformat 4.4.0

My `jupyter_nbconvert_config.json` file looks like:
```json
{
"Exporter": {
"template_path": [
".",
"/home/ktavabi/.jupyter/templates"
],
"preprocessors": [
"jupyter_contrib_nbextensions.nbconvert_support.CodeFoldingPreprocessor",
"jupyter_contrib_nbextensions.nbconvert_support.PyMarkdownPreprocessor"
]
},
"version": 1
}
```
I get the following error in the console:

> [NbConvertApp] ERROR | Exception while loading config file /home/ktavabi/.jupyter/jupyter_nbconvert_config.json
> Traceback (most recent call last):
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/site-packages/traitlets/config/application.py", line 562, in _load_config_files
> config = loader.load_config()
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/site-packages/traitlets/config/loader.py", line 406, in load_config
> dct = self._read_file_as_dict()
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/site-packages/traitlets/config/loader.py", line 412, in _read_file_as_dict
> return json.load(f)
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/json/__init__.py", line 291, in load
> **kw)
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/json/__init__.py", line 339, in loads
> return _default_decoder.decode(s)
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/json/decoder.py", line 364, in decode
> obj, end = self.raw_decode(s, idx=_w(s, 0).end())
> File "/home/ktavabi/miniconda3/envs/andrea-anders/lib/python2.7/json/decoder.py", line 382, in raw_decode
> raise ValueError("No JSON object could be decoded")
> ValueError: No JSON object could be decoded