Add correct path to sample echo binary in readme (#24)
Add correct path to sample echo binary in readme (#24)

Summary:
The current readme uses an incorrect path for the binary built after running `make test`
The current path is to the code directory.
Could lead to potential confusion.
Pull Request resolved: https://github.com/facebookincubator/mvfst/pull/24

Reviewed By: yangchi

Differential Revision: D15949456

Pulled By: udippant

fbshipit-source-id: 6f4b4c1a4592dea1f1538372bfbead8682e5d3d6

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst