Spring/Zeus preloaders issue

[antonfefilov]

I figured this issue: can't change access mode from "r+" to "a" (ArgumentError) while was using stripe-ruby-mock gem w/ both Spring and Zeus preloaders.
The problem is in https://github.com/nesquena/dante/blob/master/lib/dante/runner.rb#L253 and I'm curious is it possible to simply remove 'a' option (all is well without it) or there is should be more complex solution?

[nesquena]

Looks like maybe you don't have permission to write to the log file. You could submit a PR which catches that exception and prints a warning instead rather than erroring out.

[antonfefilov]

Thank you for quick response, I will follow your recommendation.