education: remove redundant information

[artic92]

I'd rather remove some information from this section to make more space for the photo and a more thorough description.

• [x] remove specialisation after M.Sc. degree
• [x] remove marks
• [x] coalesce university name with location
• [x] change years to final year only, e.g. 2011-2015 change to 2015 only