Add CI for unstable branches

[traversaro]

Fix #101 .

This PR is currently blocked by:

• Add ROBOTOLOGY_PROJECT_TAGS to specify which tags/branches to use for each CMake package #275
• Is there a branch compatible with YARP unstable branch?  wearables#57 (@Yeshasvitvs as mantainer of the Human Dynamics profile can you ensure that this is addressed, eventually pinging @DanielePucci for obtaining resources? Thanks!) Blocked by Compilation failing against YARP devel and master wearables#56

[DanielePucci]

I think that @Yeshasvitvs may be the right person

[yeshasvitirupachuri]

I will address it as soon as possible within this week.

[traversaro]

Blocked by robotology/wearables#56 .

[traversaro]

@lrapetti @Yeshasvitvs @DanielePucci As it CI testing of unstable branches is really useful, I strongly prefer to go forward on this, so for the time being I disabled the HUMAN_DYNAMICS component from the CI of the robotology-superbuild . However, as a release of YARP is expected at the end of this month, if robotology/wearables#56 is not fixed by then, I will be unfortunately forced to remove all the docs for HUMAN_DYNAMICS from the robotology-superbuild.