Update environment.yml

Author: jonashaag

environment.yml

@@ -33,7 +33,7 @@ dependencies:
   - gitpython  # obtain contributors from git for whatsnew
   - gitdb
   - numpydoc < 1.2  # 2021-02-09 1.2dev breaking CI
-  - pandas-dev-flaker==0.2.0
+  - pandas-dev-flaker
   - pydata-sphinx-theme
   - pytest-cython
   - sphinx