Move `mrbc` test to `mruby-bin-mrbc` gem from `mruby-compiler` gem
MODIFY
mrbgems/mruby-bin-mirb/bintest/mirb.rb
mrbgems/mruby-bin-mirb/bintest/mirb.rb
require 'open3'
+require 'tempfile'
assert('mirb normal operations') do
o, s = Open3.capture2(cmd("mirb"), :stdin_data => "a=1\nb=2\na+b\n")

RENAME
mrbgems/mruby-compiler/bintest/mrbc.rb
mrbgems/mruby-bin-mrbc/bintest/mrbc.rb
Move `mrbc` test to `mruby-bin-mrbc` gem from `mruby-compiler` gem