[DRE-maint] ruby-parser is marked for autoremoval from testing

[Debian testing autoremoval watch]

ruby-parser 3.8.2-1 is marked for autoremoval from testing on 2018-03-08

It (build-)depends on packages with these RC bugs:
888196: ruby-sexp-processor: FTBFS on ruby2.5: BOOM GOES THE STACK