Documentation `unsupported URL protocol`

Recently I get a unsupported URL protocol error in travis when running:
julia --project=docs -e 'using Pkg; Pkg.instantiate(); Pkg.add(PackageSpec(path=pwd()))'

The travis log:
https://travis-ci.org/lanl-ansi/Juniper.jl/jobs/501865325#L557

I’ve updated the documentation of the package before that error appeared but the error message doesn’t seem that this might be a problem. The command runs fine on my local machine.
According to previous builds it should clone from /home/travis/build/lanl-ansi/Juniper.jl instead of /home/ole/...

The JuMP.jl package runs the same command based on their .travis.yml:

It got messed up by running that command offline as it adds itself to the dependencies in the Manifest file.
Now it works for pull request but not for push:
In push I get the following error now:

https://travis-ci.org/lanl-ansi/Juniper.jl/jobs/501881513#L553-L554

ERROR: failed to fetch from /home/travis/build/lanl-ansi/Juniper.jl, error: GitError(Code:ENOTFOUND, Class:Odb, object not found - no match for id (af8a6f89f7d44a0345dbb7c9d0791865958f2c4f))