I see, that "Search Engine Robots" should be in "Stores / Configuration / General / Design" path. I see that this panel was there in Magento 2.1. But I cannot see "Design" section at all in the fresh Magento 2.2.0 installation:
2 Answers
Go to Content -> Design -> Configuration in admin panel
Select your current from the grid and click edit from action column.
Refer this in Content > Design > Configuration
Select your current from the grid and click edit from action column.
You will find the setting for Search Engine Robots.