Update requirements-dev.txt

Generated with:

  $ pipenv lock -r -d > requirements-dev.txt

requirements-dev.txt

@@ -1,13 +1,17 @@
 -i https://pypi.org/simple
+appdirs==1.4.3
 atomicwrites==1.3.0
 attrs==19.1.0
 backcall==0.1.0
+black==19.3b0
+click==7.0
 decorator==4.4.0
 entrypoints==0.3
 flake8==3.7.8
 importlib-metadata==0.19 ; python_version < '3.8'
 ipython-genutils==0.2.0
 ipython==7.7.0
+isort==4.3.21
 jedi==0.15.1
 mccabe==0.6.1
 more-itertools==7.2.0
@@ -27,6 +31,7 @@ pytest-clarity==0.2.0a1
 pytest==5.1.1
 six==1.12.0
 termcolor==1.1.0
+toml==0.10.0
 traitlets==4.3.2
 wcwidth==0.1.7
 zipp==0.6.0