better precommit hook - lint components too

and remove the Py2 exclusion for black while we're at it

Author: alexcjohnson

.husky/pre-commit

@@ -1 +1,3 @@
-npm run lint
+npm run lint && \
+(cd components/dash-core-components && npm run lint) && \
+(cd components/dash-table && npm run lint)

package.json

@@ -7,7 +7,7 @@
     "private::initialize.renderer": "cd dash/dash-renderer && npm ci",
     "private::build.components": "python dash/development/update_components.py 'all'",
     "private::build.renderer": "cd dash/dash-renderer && renderer build",
-    "private::lint.black": "if [ ${PYLINTRC:-x} != '.pylintrc' ]; then black dash tests --exclude metadata_test.py --check; fi",
+    "private::lint.black": "black dash tests --exclude metadata_test.py --check",
     "private::lint.flake8": "flake8 --exclude=metadata_test.py dash tests",
     "private::lint.pylint-dash": "PYLINTRC=${PYLINTRC:=.pylintrc39} && pylint dash setup.py --rcfile=$PYLINTRC",
     "private::lint.pylint-tests": "PYLINTRC=${PYLINTRC:=.pylintrc39} && pylint tests/unit tests/integration -d all --rcfile=$PYLINTRC",