Make browserify a peer dependency, lock most dependencies versions

[nolde]

• locks dependencies versions to reduce chance of unforeseen problems
  • keeping it unlocked to match serverless doesn't make a lot of sense, since serverless is usually globally installed
  • keep bluebird mostly unlocked, as it is commonly used by applications
  • dev dependencies unlocked
• make browserify a peer dependency
  • allows for better control on part of the application
  • tested with a few versions, no issues found
• some housekeeping