Install master-specific modules.

[mcollina]

I often use the level-ttl module, which I must attach only once in the 'master' process. What is the right approach? I think this use case is not handled at the moment.

I can't just add a 'promoted' event, as I need to intercept the creation of the new database. So, if it's ok for you I'll add a wrapMaster option with a function to install the master-only modules. So we can replace this line
https://github.com/substack/level-party/blob/master/index.js#L54
with:

proxy.swap(opts.wrapMaster && opts.wrapMaster(db) || db);

Shall I submit a PR?

[TehShrike]

I'm interested in a solution to this problem as well.

[vweevers]

Is this still an issue, or can it be closed?