Fix deps.joke to use source filename directly
Fix deps.joke to use source filename directly

Instead of guessing which argument, in the original invocation of Joker,
has the filename, or even using the Joker-provided *command-line-args*
variable, just use *file* directly (it's a new-ish feature).

This allows the test to pass even if Joker options (not options to the
Joker script being invoked) are provided. E.g. this works:

  ./joker --evaluate tests/run-eval-tests.joke

candid82/joker,candid82/joker,candid82/joker