Add ETL Contract Checks (#619)

* Adds dev dependencies to requirements.txt and re-runs black on codebase

* Adds test and code for national risk index etl, still in progress

* Removes test_data from .gitignore

* Adds test data to nation_risk_index tests

* Creates tests and ETL class for NRI data

* Adds tests for load() and transform() methods of NationalRiskIndexETL

* Updates README.md with info about the NRI dataset

* Adds to dos

* Moves tests and test data into a tests/ dir in national_risk_index

* Moves tmp_dir for tests into data/tmp/tests/

* Promotes fixtures to conftest and relocates national_risk_index tests:
The relocation of national_risk_index tests is necessary because tests 
can only use fixtures specified in conftests within the same package

* Fixes issue with df.equals() in test_transform()

* Files reformatted by black

* Commit changes to other files after re-running black

* Fixes unused import that caused lint checks to fail

* Moves tests/ directory to app root for data_pipeline

* Adds new methods to ExtractTransformLoad base class:
- __init__() Initializes class attributes
- _get_census_fips_codes() Loads a dataframe with the fips codes for 
census block group and tract
- validate_init() Checks that the class was initialized correctly
- validate_output() Checks that the output was loaded correctly

* Adds test for ExtractTransformLoad.__init__() and base.py

* Fixes failing flake8 test

* Changes geo_col to geoid_col and changes is_dataset to is_census in yaml

* Adds test for validate_output()

* Adds remaining tests

* Removes is_dataset from init method

* Makes CENSUS_CSV a class attribute instead of a class global:
This ensures that CENSUS_CSV is only set when the ETL class is for a 
non-census dataset and removes the need to overwrite the value in 
mock_etl fixture

* Re-formats files with black and fixes broken tox tests

data/data-pipeline/pyproject.toml

@@ -64,13 +64,14 @@ disable = [
   "C0116", # Disables missing function or method docstring
   "C0115", # Disables missing class docstring
   "R0915", # Disables too many statements (score generation transform)
+  "W0231", # Disables super init not called
 ]
 
 [tool.pylint.FORMAT]
 max-line-length = 150
 
 [tool.pylint.typecheck]
-generated-members = "pandas.*" # fixes E1101 for ETL.df 
+generated-members = "pandas.*" # fixes E1101 for ETL.df
 
 [tool.pylint.SIMILARITIES]
 # Configures how pylint detects repetitive code