Cannot add package

[jakewilliami]

I am getting the following error:

(@v1.5) pkg> add "https://github.com/JuliaOpenCV/CVCore.jl"
   Updating git-repo `https://github.com/JuliaOpenCV/CVCore.jl`
ERROR: could not find project file in package at `https://github.com/JuliaOpenCV/CVCore.jl` maybe `subdir` needs to be specified