Edit a resource by supplying a locally-modified object

[benjcunningham]

Editing resources by passing parameters is useful, but it's kind of annoying as the size of ... grows. I want to be able to capture an object, modify it locally, and push it back to the API (along the lines of an UPDATE). This way, we can do things like:

event <-
  gc_summary("Concerts") %>%
  gc_event_query(q = "Cloud Nothings")

event$summary <- "Cloud Nothings / Protomartyr"
event$location <- "Gabe's IC"

gc_event_update(event)

gc_summary("Test Calendar") %>%
  modifyList(list(
    summary = "Update Test Calendar",
    location = "NYC"
  )) %>%
  gc_update()