[2.0.7] Shows some Google Analytic reports (SEO module)

[phuoc69]

In next TomatoCMS 2.0.7, we are going to use Google Analytic API to show some popular reports in chart:

The list of most useful charts should be:
- Percentage of number of visits based on the user's web browser
- Percentage of number of visits based on the user's operating system
- Number of visits/pageviews in last week/month/year