fixup black dep installation

Author: Gr1N

.gitignore

@@ -54,7 +54,7 @@ wheels/
 *.egg-info/
 .installed.cfg
 *.egg
-pyproject.lock
+poetry.lock
 
 # PyInstaller
 #  Usually these files are written by a python script from a template

pyproject.toml

@@ -47,7 +47,7 @@ python = "^3.6"
 dataclasses = { version = "*", python = "~3.6" }
 
 [tool.poetry.dev-dependencies]
-black = "*"
+black = { version = "*", allows-prereleases = true }
 flake8 = "*"
 flake8-bugbear = "*"
 isort = "*"

tox.ini

@@ -41,15 +41,13 @@ deps =
 [testenv:py36-tests]
 commands =
     poetry install -v
-    poetry develop
     pytest -vv {posargs:tests/}
 whitelist_externals =
     poetry
 
 [testenv:py37-tests]
 commands =
     poetry install -v
-    poetry develop
     pytest --cov-report term --cov-report html --cov=pynats -vv {posargs:tests/}
 whitelist_externals =
     poetry