test against latest ruby

pack('m0') to avoid newlines

use bacon properly (don't pollute top level)

just let travis use latest mri if possible

need to put rubysl-benchmark in toplevel as well...

rubysl-benchmark for activesupport

there's little points to test Psych now

ditto

rubysl-bigdecimal for crack

bump gemspec

rubysl-base64 for em-socksify for em-http-request

so we need rubysl-fiber for rbx?

adopt latest muack

bump task

bump Gemfile and year