Feature Request: Flush writeInstructionsFile on change

[bmalinconico]

I'm using Delve through vim-test. One of the problems with that integration is that vim-test is writing it's own init file and calling tests agains that.

This means that if i run tests then change my breakpoints the new breakpoints will not be picked up until I re-run vim-test. I would like to be able to use the vim-test re-run command with new breakpoints.

While I realize this is a vim-test problem, however I think this would best be solved by adding an upstream feature to keep the command file up-to-date. That would allow vim-test to instead hook into the file provided by vim-delve.

If you are amenable to this feature I think I can handle the addition of it. Please let me know.