Rename license-report.md to avoid misuse by GitHub

[alexander-yevsyukov]

Here's how it looks now:

GitHub sees a file which starts with license and grabs it into its UI. It's funny, but misleading for the visitors.

Here's what we need to do:

• Adjust the build scripts so that the generated file does not start with license. It could be dependency-licenses.md or just dependencies.md. People would find their way.
• Adjust the code of spine.io site so that it picks up renamed files.

[alexander-yevsyukov]

@armiol, FYI.