Fix conda test to account for newer conda

tests/conda/binder-dir/verify

@@ -5,6 +5,6 @@ from subprocess import check_output
 assert sys.version_info[:2] == (3, 5), sys.version
 
 out = check_output(["conda", "--version"]).decode("utf8").strip()
-assert out == "conda 4.7.12", out
+assert out == "conda 4.8.2", out
 
 import numpy