Drop old compat

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>

Author: simsurace

docs/Project.toml

@@ -8,7 +8,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
 Distances = "0.10"
-Documenter = "0.27, 1"
+Documenter = "1"
 KernelFunctions = "0.10"
 Kronecker = "0.4, 0.5"
 PDMats = "0.11"