Merge pull request #175 from mithro/python3.8-fix

env: Lock to Python 3.8
diff --git a/environment.yml b/environment.yml
index 18e9369..e46f745 100644
--- a/environment.yml
+++ b/environment.yml
@@ -19,7 +19,7 @@
 - conda-forge
 - defaults
 dependencies:
-- python
+- python=3.8
 - pip
 - yosys
 - netlistsvg