Adding global population data

Added data
Closes ukodi/ODP-Group2#2
Adding map section to webpage (and population)

Added map and population data
Closes ukodi-training/ODP-Group2#2
Closes ukodi-training/ODP-Group2#4
Display name of country and population

Added data.
Closes ukodi-training/ODP-Group2#1
Merge pull request #6 from priyanka-bhatt/gh-pages

Map for milestone 1