core-test: bump to v0.13

[greut]

Upgrade core-test to v0.13, https://github.com/editorconfig/editorconfig-core-test/releases/tag/v0.13

Some tests had to be skipped.

97% tests passed, 5 tests failed out of 193

Total Test time (real) =  18.12 sec

The following tests FAILED:
        159 - escaped_octothorpe_in_property (Failed)
        163 - max_property_name (Failed)
        164 - max_property_value (Failed)
        165 - max_section_name_ok (Failed)
        166 - max_section_name_ignore (Failed)

[xuhdev]

The failure may be realted to editorconfig/editorconfig-core-test#29 and #17

[xuhdev]

Since #20 has been merged, could you rebase and let CI rerun the test?