pin packages on RTD (#768)
pin packages on RTD (#768)

* try pin packages on RTD

* add deps

* also pin manually added packages

anoukvlug/oggm,OGGM/oggm,juliaeis/oggm,TimoRoth/oggm,anoukvlug/oggm,OGGM/oggm,TimoRoth/oggm,juliaeis/oggm,bearecinos/oggm,bearecinos/oggm