Add dependency on readline-native to fix the following issue
uninitialized constant Logfile
| Check ext/fiddle/mkmf.log for more details.
| readline:
| Could not be configured. It will not be installed.
|
build/tmp/work/x86_64-linux/ruby-native/2.5.1-r0/ruby-2.5.1/ext/readline/extconf.rb:62:
Neither readline nor libedit was found
| Check ext/readline/mkmf.log for more details.
| *** Fix the problems, then remove these directories and try again if
you want.
