Fix REPL of better_errors page

The gem better_errors Show archive.org snapshot offers a detailed error page with an interactive REPL Show archive.org snapshot for better debugging.
I had the issue that on a few projects with Ruby 2.5.8, the REPL was not shown.

Solution

To make the REPL work properly with this Ruby version I had to update the gem binding_of_caller Show archive.org snapshot to at least version 0.8.0.

From the better_errors Show archive.org snapshot docs:

binding_of_caller is optional, but is necessary to use Better Errors' advanced features (REPL, local/instance variable inspection, pretty stack frame names).