Update project name in printed '--version'

[jeremyh]

• The project name is now "Open Data Cube", not just "Data Cube"
• When using the Click arguments in other scripts, it's worth clarifying that the version printed is the core version, not the script version, so I've appended 'core'.

Flashy demo:

jez@kveikur:~/prog/datacube (develop) $ datacube --version
Open Data Cube core, version 1.4.1+100.ged4183b
jez@kveikur:~/prog/datacube (develop) $ 

[omad]

Groovy. I love beautification.

[coveralls]

Coverage remained the same at 81.781% when pulling 8eaf1c3 on jeremyh:version into ee8687b on opendatacube:develop.