Gem fix

@headius you forget to push your head (0.1.2).

I released 0.1.3, as I was trying to fix #20 - I thought that since https://rubygems.org/gems/atomic was installing fine, this must be because its non-java version was pushed last (after the -java version that is). So I tried the same trick with thread_safe, and seemed to work for some time, but then also broke (at least on my local machine).