travis check for documenter

Author: j-fu

.travis.yml

@@ -33,7 +33,7 @@ jobs:
       julia: 1.1
       os: linux
       script:
-        - julia --project=docs/ -e 'using Pkg; println("1"); Pkg.add("Documenter");  println("2"); Pkg.update(); println("3"); Pkg.develop(PackageSpec(path=pwd())); println("4"); Pkg.instantiate();  println("5");'
+        - julia --project=docs/ -e 'using Pkg; println("1"); Pkg.add(PackageSpec(name="DocStringExtensions", version="0.8.0")); println("1a"); Pkg.add("Documenter");  println("2"); Pkg.update(); println("3"); Pkg.develop(PackageSpec(path=pwd())); println("4"); Pkg.instantiate();  println("5");'
         - julia --project=docs/ docs/make.jl
       after_success: skip