Jupyter Notebook: Can't parse config file

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The example Jupyter Notebook can't be run as there seems to be an issue reading the example config file:
```
singleConfig = ConfigFileReader(singleConfigPath)
```

Causes the following error:
```
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
in
1 # Read config file.
----> 2 singleConfig = ConfigFileReader(singleConfigPath)

C:\temp\Anaconda\lib\site-packages\callflow\operations\read_config.py in __init__(self, filepath, config_json)
31
32 self.scheme = self.json["scheme"]
---> 33 self.datasets = self.json["datasets"]
34 self.runName = self.json["run_name"]
35 self.save_path = os.path.join(self.data_path, ".callflow")

KeyError: 'datasets'
```

Config file: hpctoolkit-cpi-database/callflow.config.json
Environment: CallFlow 1.1.1 / Jupyter Notebook 6.0.3 / Anaconda Python 3.7.6 / Win10 64bit

Reproduce the failure using hpctoolkit-cpi-database/callflow.config.json and the example Jupyter Notebook. Start at ConfigFileReader in callflow/operations/read_config.py, where the traceback shows the missing datasets key is read. Done means the example notebook can load the configuration without the KeyError.

Written by the indexing model from the issue text.