Warning message should be displayed in case of misconfigured "tsconfig.json"

[mnasyrov]

Currently tsconfig-paths fails in case tsconfig.json does not declared "paths" settings.
It will be better to display a meaningful warning or error message instead.

[Jontem]

I've implemented it as warning message in version 2.1.2.

If tsconfig.json or paths in compilerOptions is missing it will show a warning message and will not patch Module._load. So it would work as ts-node without tsconfig-paths.

But if baseUrl is missing from compilerOptions we will also show a warning message but typescript itself will throw an exception about missing the baseUrlproperty.