conditionals for compatibility with other versions

[StefanKarpinski]

Specifically, older versions of julia which didn't have UniformScaling and older (newer?) versions of StatsBase which don't have range defined.

[simonster]

We've dropped support for Julia 0.2, so I'm not sure we need to worry about UniformScaling? (I'm not sure how broken the rest of the package is with out-of-date Julia 0.3 prereleases, but I know the tests will fail on any build older than the hashing changes.)

I think we should just remove StatsBase.range, since it was removed from newer versions of StatsBase.

[StefanKarpinski]

I – and I suspect other people – still have to support older versions of 0.3-prerelease. It seems reasonable to do simple things like this to allow the package to work with a broader range of Julia versions.

[simonster]

Ah, ok. I guess loading under older versions of 0.3-prerelease is better than not loading, but some functionality is still likely to be broken. To avoid breaking functionality on older prereleases, ideally we'd have something like JuliaLang/julia#5892, or we'd specify the necessary prerelease version in REQUIRE and leave older prereleases on older package versions (which should already work in theory, but broke with the Ubuntu binaries when I tried it). Or we'd just have a faster release cycle ;)