Deal with virtualenv 1.11.0 in a few more places.
Merge pull request #45 from mdboom/benchmark-discovery-in-subprocess

Benchmark discovery should be agnostic to installation of benchmarked package
Merge pull request #64 from mdboom/ez_setup/2_1

Upgrade `ez_setup.py`
Merge pull request #59 from mdboom/run/default-arg

Default argument to `asv run` should be `master`
Improve test coverage