Update dependencies

[dougmoscrop]

I finally looked in to why I was seeing this:

npm ERR! peer dep missing: ajv@^5.0.0, required by ajv-keywords@2.1.1
npm ERR! peer dep missing: ajv@^5.0.0, required by ajv-keywords@2.1.1

$ npm ls ajv-keywords
...
└─┬ rewire@4.0.1
  └─┬ eslint@4.19.1
    └─┬ table@4.0.2
      └── ajv-keywords@2.1.1

Updating the deps and linking in rewire made these error messages go away.

[coveralls]

Coverage remained the same at 97.619% when pulling dc52108 on dougmoscrop:master into 5bea3d8 on jhnns:master.

[rensbaardman]

This would also fix #154 and #166.

[cjancsar]

@jhnns can you please merge this?

[octopotato]

@jhnns any update on this?