Hi,
back on this more than 2 months later...
so I setup travis to upload ossia package to deken on tagged commit.
The deken configuration and GPG key are encrypted with travis command line tool.
I'm not using deken tool on travis because I had too much headache.
But it should be possible,
At least I can upload some non signed package.
Moreover I have a lot of issue on Appveyor to run deken.
PATH variable is a nightmare to configure and deken fails because it can't find `make`...
Those issues discouraged me to use the command line tool and I'm using `curl` to create directory and upload file.
gpg sign the package and sha256-sum compute the checksum.
This setup is working on Travis, Appveyor is on the road.
Concerning the parenthese issue, you should use at least single quotes around your file name.
I'm using double ones to expand ${VERSION} variable *before* making the upload URL.
cheers
Antoine