Add lint target to Makefile.

Author: albu-diku

Makefile

@@ -52,6 +52,10 @@ distclean: clean
 	@rm -rf ./tests/__pycache__
 	@rm -f ./tests/*.pyc
 
+.PHONY: lint
+lint:
+	@./envhelp/python2 -m flake8 . --exclude=tests,state,envhelp,fixture,output,unittest,grsfs-fuse,irclib.py,seafile-seahub_settings-template.py --count --select=E9,F63,F7,F82 --show-source --statistics
+
 .PHONY: test
 test: dependencies testconfig
 	@$(PYTHON_BIN) -m unittest discover -s tests/

local-requirements.txt

@@ -3,6 +3,7 @@
 # This list is mainly used to specify addons needed for the unit tests.
 # We only need autopep8 on py 3 as it's used in 'make fmt' (with py3)
 autopep8;python_version >= "3"
+flake8;python_version < "3"
 # We need paramiko for the ssh unit tests
 # NOTE: paramiko-3.0.0 dropped python2 and python3.6 support
 paramiko;python_version >= "3.7"