Adds National Risk Index data to ETL pipeline (#549)

* 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

data/data-pipeline/data_pipeline/tests/conftest.py

@@ -0,0 +1,33 @@
+import os
+
+import pytest
+
+from data_pipeline.config import settings
+from data_pipeline.etl.base import ExtractTransformLoad
+
+TMP_DIR = settings.APP_ROOT / "data" / "tmp" / "tests"
+
+
+@pytest.fixture(scope="session")
+def mock_paths(tmp_path_factory) -> tuple:
+    """Creates new DATA_PATH and TMP_PATH that point to a temporary local
+    file structure that can be used to mock data folder during testing
+    """
+    # sets location of the temp directory inside the national_risk_index folder
+    os.environ["PYTEST_DEBUG_TEMPROOT"] = str(TMP_DIR)
+    TMP_DIR.mkdir(parents=True, exist_ok=True)
+    # creates DATA_PATH and TMP_PATH directories in temp directory
+    data_path = tmp_path_factory.mktemp("data", numbered=False)
+    tmp_path = data_path / "tmp"
+    tmp_path.mkdir()
+    return data_path, tmp_path
+
+
+@pytest.fixture
+def mock_etl(monkeypatch, mock_paths) -> None:
+    """Creates a mock version of the base ExtractTransformLoad class and resets
+    global the variables for DATA_PATH and TMP_PATH to the local mock_paths
+    """
+    data_path, tmp_path = mock_paths
+    monkeypatch.setattr(ExtractTransformLoad, "DATA_PATH", data_path)
+    monkeypatch.setattr(ExtractTransformLoad, "TMP_PATH", tmp_path)