Bootstrapping MPI Bindings

[carsonwoods]

As part of the effort to convert Lemonspotter to use the bindings built into the MPI standard, we are inherently requiring access to the MPI standard. I think that is a reasonable requirement given the intended audience of the tool, however I still think we should provide some mechanism to bootstrap the apis.json file that is generated when compiling the standard.

Right now, an easy way to do that would be to add a bootstrap command which will fetch a copy of the file. We could fetch this by storing it somewhere and updating our stored copy periodically or we could assume the user has access to the MPI standard and could download and build the apis.json file that way. The second way requires some hefty dependencies though and that could be impractical.

Alternatively to all of the other options, we could just include a copy of the apis.json file in the repository itself. We'd need to eventually divorce the two again (or always provide an updated copy), but this could be a reasonable stop-gap measure.