Move Black-based auto-formatting to pre-commit

Disclaimer:
Participation by NIST in the creation of the documentation of mentioned
software is not intended to imply a recommendation or endorsement by the
National Institute of Standards and Technology, nor is it intended to
imply that any specific software is necessarily the best available for
the purpose.

References:
* [AC-215] Evaluate pre-commit usage on casework repositories
* [AC-216] Apply Black to all casework Python code bases
* #37

Signed-off-by: Alex Nelson <alexander.nelson@nist.gov>

Author: ajnelson-nist

tests/Makefile

@@ -67,17 +67,6 @@ check: \
 	    --ignore case_utils \
 	    --log-level=DEBUG
 
-# TODO - Need to settle on policy for incorporating this and 'format' recipe into CI.
-# https://case.atlassian.net/browse/AC-215
-# https://case.atlassian.net/browse/AC-216
-check-black: \
-  .venv.done.log
-	source venv/bin/activate \
-	  && black \
-	    --check \
-	    $(top_srcdir)/case_utils \
-	    $$PWD
-
 check-case_utils: \
   .venv.done.log
 	$(MAKE) \
@@ -112,13 +101,3 @@ clean:
 
 download: \
   .venv.done.log
-
-# TODO - Need to settle on policy for incorporating this and 'check-black' recipe into CI.
-# https://case.atlassian.net/browse/AC-215
-# https://case.atlassian.net/browse/AC-216
-format: \
-  .venv.done.log
-	source venv/bin/activate \
-	  && black \
-	    $(top_srcdir)/case_utils \
-	    $$PWD

tests/requirements.txt

@@ -1,5 +1,4 @@
 PyLD
-black
 mypy
 pytest
 python-dateutil