Clear Error Message for Whitespace Issues

[jackdesert]

Perhaps there could be a clear error message for whitespace issues.

For example, this checks file works:

checks for agr_one_file:
    - custom_test_count = 8000000:
        custom_test_count query:  SELECT max(zip) FROM agr_one_file

But this checks file (the same except the last line has two less leading spaces) generates an error.

checks for agr_one_file:
    - custom_test_count = 8000000:
      custom_test_count query:  SELECT max(zip) FROM agr_one_file

Here is the error that is generated using the latter file:

(soda) @ws soda-core-example soda scan -d source_one -c configuration.yml checks-two-spaces.yml
Soda Core 3.0.5
Could not add SodaCL file checks-two-spaces.yml
  | 'NoneType' object is not iterable
Scan summary:
No checks found, 0 checks evaluated.
1 errors.
Oops! 1 error. 0 failures. 0 warnings. 0 pass.
ERRORS:
Could not add SodaCL file checks-two-spaces.yml
  | 'NoneType' object is not iterable

It took us a while to determine it was a whitespace issue.

[jmarien]

SODA-1206