Failed load pubspec.yaml if contains dependencies from self hosted pub

[ekasetiawans]

Failed load pubspec.yaml if contains dependencies from self hosted pub

[dnys1]

The issue is in the ExternalHostedReference parsing. The hosted reference can take two forms, neither of which matches the JSON serialization in this package.

With sdk: >=2.15.0

dependencies:
  transmogrify:
    hosted: https://some-package-server.com
    version: ^1.4.0

Pre-2.15.0

dependencies:
  transmogrify:
    hosted:
      name: transmogrify
      url: https://some-package-server.com
    version: ^1.4.0