Add mwparams to namespace?

[johnrharley]

Thanks for writing up this package. It's been a useful wrapper for the Mesowest API.

I notice that the function mw() is dependent on the mwparams data from the getparams() function. As is, you cannot use the mw() call without loading the package. So

mesowest::mw(service="metadata", complete=1, state="AK")

throws up the warning "In data(mwparams) : data set 'mwparams' not found" (same with other mw() calls).

The mwparams data seem to be fairly static, so maybe add those data to the namespace?