Add local_caller method Sometimes you want a stack trace of what chain of methods invoked wherever you are right now. `caller` does this, but it also includes things like library and irb/pry frames in the stack. Often what I want is the stack frames from whatever code is in the current code base. `local_caller` uses the current directory as a proxy for "current code base". It `select`s the frames that contain `Dir.pwd` which leaves us with a nice, small stack trace. This is on `Kernel` so it can be uses anywhere.