Add unit property and as_unit method to Timestamp, Timedelta and NaTType
#2248
| Job | Run time |
|---|---|
| 12s | |
| 2m 44s | |
| 2m 57s | |
| 2m 45s | |
| 3m 19s | |
| 5m 38s | |
| 5m 26s | |
| 5m 38s | |
| 5m 48s | |
| 5m 34s | |
| 3m 27s | |
| 4m 5s | |
| 4m 19s | |
| 51m 52s |