dockerfile uses pypi release

[Remi-Gau]

I am fixing the circle CI workflows of a lot of bids apps and having a quick look at the one of rsHRF.

Ideally we want the unit test to run regularly (with every push or merge to master) and not just on release.

Also we want to test the docker build regularly and possibly push an "unstable" image to docker hub that corresponds to the HEAD of the master branch.

Currently the dockerfile is set to install rsHRF from pypi which means that even if we make changes on the master branch the "unstable" docker image will be lagging behind.

One possible solution is to modify the dockerfile to copy the rsHRF code in it and install the package there.