Make the codename dynamic for nodes PPA file and  remove the eventually previously installed, else apt_add doesn't install the new one.
implement install_components() for a local development environment on Ubuntu.
bump version in setup.py
Merge branch 'release/2.7'
Merge tag 'sparks-2.7' into develop

2.7
make a message more meaningful.
bump version in setup.py
Merge branch 'release/2.7.1'
Merge tag 'sparks-2.7.1' into develop

2.7.1