Fixnums are frozen in ruby 2.0.0
Increase test coverage to 100%
Merge pull request #3 from bwthomas/fixnums_are_frozen

Fixnums are frozen in ruby 2.0.0
Merge pull request #4 from bwthomas/complete_test_coverage

Increase test coverage to 100%
run against 2.1.0
rm pending specs re:features no one uses
MIT license
Warn about .size, .each, etc in README

Closes #5

Despite the lack of a particularly good resolution to this. =\

I want enumerability, though, more than I want to name keys `:size`.
merge in upstream