For similarity corpora from in 0.2

[oxinabox]

Right now if we merge #8

We will lose:

• [ ] SWSC
• [ ] WordSim353

Old code is at:

• https://github.com/JuliaText/CorpusLoaders.jl/blob/65f349bbdf285fc3dda4139454e0b59079174ab9/src/similarity.jl

It needs porting to the new style These are not traditional shaped corpora being for tasks. Will need to think on best representation