Update libraries to fix vulnerabilities

[fernahh]

When I ran the npm audit command, the tool had found 460 vulnerabilities:

found 460 vulnerabilities (374 low, 80 moderate, 6 high) in 26043 scanned packages
  run `npm audit fix` to fix 460 of them.

After I've ran npm audit fix:

▶ npm audit fix
+ babel-preset-env@1.7.0
+ eslint@4.19.1
+ babel-core@6.26.3
added 22 packages from 38 contributors, removed 28 packages, updated 34 packages and moved 1 package in 11.566s
fixed 460 of 460 vulnerabilities in 26043 scanned packages