Create PHP (Composer) OSS Index client MVP

[ken-duck]

Create a PHP OSS Index client, with the following features:

• Command line tool
• Written in PHP

Basic Features

• Reads package dependencies from the appropriate PHP "composer" package file(s)
  • Preferably determines transitive dependencies
• Request known vulnerabilities for the dependencies from OSS Index.
  • Use the POST API at OSS Index
  • Note the maximum of 128 packages per request
• Report to console the packages scanned and detected vulnerabilities, in the style of other OSS Index command line auditing tools