Temporary directory causes issues when Eslint rule import/no-unresolved is used

[adekbadek]

This lib creates a tmp directory with changed files only, in order to lint them. However this causes issues when using Eslint rule import/no-unresolved. When a changed file (changed line, to be precise) imports another file, which was not changed (not incl. in the git diff), this rule check will fail. The solution can be to copy the whole codebase into the tmp directory, not just the changed files.