i18n use monent relative time concept

Hello, it nice to find moment-precise-range, but it doesn't support i18n, so I added i18n support with monent relative time concept.

One thing not good is that, now 'a' will replace '1', eg. '1 month' -> 'a month'
but moment did like this, make be it will change in the future, probably moment-precise-range with i18n support can still work.