[AG-33] Parse "license" field from podspec files inside GitHub repositories

[felipead]

The following dependency was declared using a GitHub repository:

pod 'Touchy', :git => 'https://github.com/paweldudek/touchy.git'

From a Podfile.

When analyzing its GitHub repository, we can see that the repository has no license inferred from GitHub. It also has no LICENSE or README files.

However, it has a *.podspec file at https://github.com/paweldudek/Touchy/blob/master/Touchy.podspec, and within this file a license is declared:

  s.license      = "MIT"