Tests

[garrettwrong]

Should make test suite (probably easiest from python, which will also check the bindings). Testing topics:

• Reference repro in 1D
• twiddle algo params
• multiple sizes (try to catch any index oversights)
• multiple R^N
• test metric-ness
• reduce reference array to the 10x20 case (more useful now..)
• check we handle OOM

[garrettwrong]

Have covered most of the cases above, todo:

• twiddle algo params
• test metric-ness
• check we handle OOM