message: Fix spectests link in readme
diff: @@ -108,7 +108,7 @@ cargo install --path .
  ## Testing
  -Thanks to [spectests](https://github.com/wasmerio/wasmer/tree/master/spectests) we can assure 100% compatibility with the WebAssembly spec test suite.
  +Thanks to [spectests](https://github.com/wasmerio/wasmer/tree/master/lib/runtime-core/spectests) we can assure 100% compatibility with the WebAssembly spec test suite.
  Tests can be run with:
  