dev-env: Remove flake8 target from makefile.

We previously removed flake8 from our development environment.
This is a follow up which removes it also from the makefile.

Makefile

@@ -1,47 +1,39 b''
 
 WEBPACK=./node_modules/webpack/bin/webpack.js
 GRUNT=grunt
 NODE_PATH=./node_modules
-FLAKE8=flake8 setup.py pytest_pylons/ rhodecode/ --select=E124 --ignore=E711,E712,E510,E121,E122,E126,E127,E128,E501,F401 --max-line-length=100 --exclude=*rhodecode/lib/dbmigrate/*,*rhodecode/tests/*,*rhodecode/lib/vcs/utils/*
 CI_PREFIX=enterprise
 
 .PHONY: docs docs-clean ci-docs clean test test-clean test-lint test-only
 
 
 docs:
 	(cd docs; nix-build default.nix -o result; make clean html)
 
 docs-clean:
 	(cd docs; make clean)
 
 ci-docs: docs;
 
 
 clean: test-clean
 	find . -type f \( -iname '*.c' -o -iname '*.pyc' -o -iname '*.so' \) -exec rm '{}' ';'
 
 test: test-clean test-only
 
 test-clean:
 	rm -rf coverage.xml htmlcov junit.xml pylint.log result
 
-test-lint:
-	if [ "$$IN_NIX_SHELL" = "1" ]; then \
-		$(FLAKE8); \
-	else \
-		$(FLAKE8) --format=pylint --exit-zero > pylint.log; \
-	fi
-
 test-only:
 	PYTHONHASHSEED=random py.test -vv -r xw --cov=rhodecode --cov-report=term-missing --cov-report=html rhodecode/tests/
 
 web-build:
 	NODE_PATH=$(NODE_PATH) $(GRUNT)
 
 web-test:
 	@echo "no test for our javascript, yet!"
 
 docs-bootstrap:
 	(cd docs; nix-build default.nix -o result)
 	@echo "Please go to docs folder and run make html"