SRM gone in macOS Sierra (10.12)
From this comment:


  can you come up with a better idea or safely removing files from SSD
  on newer macs? – Niktin Roman 


There's no need for srm; provided that TRIM is enabled on your machine1

TRIM support handles this for you. When you delete a file from your drive, the OS will mark the file space as "not in use" - this applies to  any drive. On an SSD, unlike a HDD,  a TRIM command is sent to wipe any data in that marked space.  This allows your SSD to be able to write data to that marked space as if it was brand new and never used, and  skip the traditional  deletion process.

If you are looking for more security, turn on FileVault.

Per Apple Support:


  Note: With an SSD drive, Secure Erase and Erasing Free Space are not
  available in Disk Utility. These options are not needed for an SSD
  drive because a standard erase makes it difficult to recover data from
  an SSD. For more security, consider turning on FileVault encryption
  when you start using your SSD drive.


I also advise against using srm because it issues more and unnecessary write operations to the SSD, thus shortening it's lifespan.  From the man page:


srm  removes  each  specified file by overwriting, renaming, and
truncating it before unlinking



1 TRIM comes enabled by default if you your Mac came with an SSD preinstalled.  if you added an SSD after the fact, then you must enable TRIM by issuing the command sudo trimforce enable in Terminal.