Use 1000 as multiplier for Mbit/s and kbit/s

Speedtest.net defines Mbit/s and kbit/s using 1000 as multiplier, <https://support.speedtest.net/entries/21057567-What-do-mbps-and-kbps-mean->.
Merge pull request #14 from mihaic/units-fix

Use 1000 as multiplier for Mbit/s and kbit/s