Update lodash to solve moderate security issue

[jmendiara]

The audit report executed with npm audit says:

  Moderate        Prototype Pollution                   
  Package         lodash                                         
  Patched in      >=4.17.11                                      
  Dependency of   gatsby-remark-relative-images
  Path            gatsby-remark-relative-images > lodash  
  More info       https://npmjs.com/advisories/782         

[danielmahon]

@jmendiara Thanks!

[alanonthegit]

@danielmahon has this made it into the latest release? I'm still seeing the npm audit issues and I'm on 0.2.1. Thanks!