feat: expose leakyReluAlpha

very small feature, large consequences

fix: bump version and build

fix: Include index.js in build (oops!)

fix: Weight loss.

Merge pull request BrainJS#281 from BrainJS/185-cross-validation-fixes

fix: Fix CrossValidate to have tests for when data too small

Merge pull request BrainJS#275 from BrainJS/cleanup-api

Cleanup api for TrainStream, CrossValidate, and Typescript

Merge pull request BrainJS#261 from BrainJS/260-error-rate

fix: Error rate scale

chore: Increment and ready for release

bump version and build

Merge pull request BrainJS#200 from BrainJS/199-fix-export

fix BrainJS#199 - Properly export on es5 module