codemetar 0.3.0

• write_codemetar() can now be called from anywhere within a package directory structure. (#305, @mpadge)
• Breaking change: write_codemeta() writes the JSON file at path relative to pkg, not the current directory. (#303, @ThierryO)
• Added documentation for changing the default branch (#302, @jonkeane)
• Breaking change: Relatedly, it is no longer possible to use write_codemeta() on an installed packages, in that case one would have to use create_codemeta() together with jsonlite::write_json().
• Use R.Version() instead of R.version to allow mocking in tests.
• Bug fix: now able to parse a README where badges are in a table with non badges links.
• Bug fix: guess_fileSize() properly handles .Rbuildignore (#299, @ThierryO).
• Bug fix: create_codemetar() handles minimal packages (#298, @ThierryO).