tests fix

Update package.json

updating neighbor joining documentation

Update README.md

Merge pull request #109 from veg/issue107-hotfix

Update docs to reflect npm incompatibility, work with node 10.

Merge branch 'master' of https://github.com/veg/phylotree.js

Merge pull request #68 from stephenshank/master

Updates for revision

Merge pull request #58 from stephenshank/master

Adds a link to documentation.

bumping version to 0.1.6

Merge pull request #38 from stevenweaver/master

package.json updates