Add gram_force unit and organize Force and Pressure tests.
#625
| Job | Run time |
|---|---|
| 1m 26s | |
| 1m 15s | |
| 1m 10s | |
| 3m 16s | |
| 1m 40s | |
| 1m 37s | |
| 1m 14s | |
| 2m 55s | |
| 3m 12s | |
| 2m 34s | |
| 2m 22s | |
| 4m 17s | |
| 26m 58s |