Pass context.view to partials function

[taylorc93]

This idea arose from a project that I'm working on where I need to handle the logic for loading my own partials. This is because there might be hundreds of partials and I don't want to load all of them into memory (AKA using a partials object).

From parsing through the source code, I saw that the partials parameter for renderPartial can be a function. Great! However, when rendering through a function, I also need access to the context for the partial and currently, only the name of the partial is provided. This is where this PR comes is 😄.

[phillipj]

Thanks for contributing 👍

This sounds good to me. Could you add a test ensuring this works as intended?

[taylorc93]

Sure thing! Busy tonight but will do this tomorrow

[taylorc93]

Sorry for the delay, got caught up with other things. I noticed while trying to add a test that there was no check for retrieving partials using a function rather than an object, so that's what the test I wrote ensures. To do so however, I had to modify test/render-test.js slightly. Please advise if you have a better solution in mind or need anything else before merging.