Fix access to catalog dict

[lpillmann]

Description of change

This PR fixes the dict access bug cited in the issue #6. Previously, the code broke when running in sync mode

python \{\{cookiecutter.package_name\}\}/__init__.py -c sample_config.json --properties catalog.json

with this error:

CRITICAL 'dict' object has no attribute 'streams'
Traceback (most recent call last):
  File "{{cookiecutter.package_name}}/__init__.py", line 95, in <module>
    main()
  File "/Users/luipillmann/opt/anaconda3/envs/singer-template/lib/python3.7/site-packages/singer/utils.py", line 229, in wrapped
    return fnc(*args, **kwargs)
  File "{{cookiecutter.package_name}}/__init__.py", line 92, in main
    sync(args.config, args.state, catalog)
  File "{{cookiecutter.package_name}}/__init__.py", line 64, in sync
    selected_stream_ids = get_selected_streams(catalog)
  File "{{cookiecutter.package_name}}/__init__.py", line 54, in get_selected_streams
    for stream in catalog.streams:
AttributeError: 'dict' object has no attribute 'streams'

The error was caused by wrong syntax to access dict values in Python. The code used dot notation (my_dict.key), whilst the right syntax is either with brackets (my_dict["key"]) or using the get method (my_dict.get("key"). I chose the former option, since I consider it more readable.

Manual QA steps

Add a file catalog.json in singer-tap-template/{{cookiecutter.project_name}} with the contents provided when running python \{\{cookiecutter.package_name\}\}/__init__.py -c sample_config.json --discover.

Then, run

python \{\{cookiecutter.package_name\}\}/__init__.py -c sample_config.json --properties catalog.json

from singer-tap-template/{{cookiecutter.project_name}} folder. The expected behavior is no return with no errors.

Risks

No risks since this addresses only a few lines of code with very limited scope.

Rollback steps

• revert this branch

[aaronsteers]

replaced by #11