Bump dcos-docs
Bump dcos-docs

Bump dcos/dcos-docs
  Karl Isenberg:
     Fix image types (#1173)
  Stephanie Bodoff:
     Sb/docs 1998 (#1171)
  joel-hamill:
     Change IOT tutorial title

dcos/dcos-website,dcos/dcos-website,dcos/dcos-website,dcos/dcos-website