Revert "Tentatively fix #83. Would only happen on some old 2.7 that don't have checK_output but has the exception class."
Revert "Tentatively fix #83. Would only happen on some old 2.7 that don't have checK_output but has the exception class."

This reverts commit 48c5f459057a9c9853a2fba24217b58e74d183de.

It was bad, utils.check_output needs the custom exception.

ionelmc/pytest-benchmark