GitLab

**Major Revision**

- Add an option for pattern to generate mpi_pattern.txt file if
specified the path.
- In mpi pattern, serial_index and parallel_index will add in each
benchmark as environment variables.

**Minor Revision**
- Fix typo

**Description**
Support the following patterns  in `mpi` mode:
* `k-batch`
* `topo-aware`

* Extract pair-wise pattern from ib_validation