test: bump test-run to version w/ updated luatest

Bump test-run to new version with the following improvements:

- Bump luatest to 0.5.7-17-g1387aa8 [1]

[1] tarantool/test-run#360

Part of tarantool/luatest#239

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff