wrapper code

[amcnicho]

Installing the project into each test environment from pre-published wheels instead of building it from the repository state (see #1) means that some "glue" code will be needed to automate the process of updating the asv infrastructure to produce a desired set of results from repeated asv run calls made against a single VCS tag at a time.

Define the interface and implementation for wrapper logic that updates the asv configuration and then executes against the range of commits requested for a given set of wheels and tests. This wrapper should support both use cases (published builds of main trunk and development builds of feature branches).