[conda] Unpin (again) conda=4.6 - does not really work on base environment

bob/devtools/bootstrap.py

@@ -422,7 +422,7 @@ if __name__ == "__main__":
     with open(condarc, "wt") as f:
         f.write(_BASE_CONDARC)
 
-    conda_version = "4.6"
+    conda_version = "4"
     conda_build_version = "3.16"
     conda_verify_version = "3"
 

conda/meta.yaml

@@ -31,7 +31,7 @@ requirements:
     - black >=19
     - click >=7
     - click-plugins
-    - conda=4.6
+    - conda=4
     - conda-build=3.16
     - conda-verify=3
     - certifi