Update shadowed operators

[kevmal]

Closes #332

round and log10 in FSharp.Stats.Ops (which is auto opened) shadows existing operators. log10 is equivalent and unneeded. round has a different signature than the existing round function.

Changes:

• remove log10 which is already available
• rename round to roundTo

[Required] please make sure you checked that

• The project builds without problems on your machine

[Optional]

• Added unit tests regarding the added features

[smoothdeveloper]

if we are making breaking changes to Ops members, maybe a good time to remove the AutoOpen?

[bvenn]

I thought about adding an obsolete tag to the Ops.fs, but as this just reinstates the previous state that should've been changed, I'm going to merge this PR as it is.

[<AutoOpen>]
[<Obsolete("Ops AutoOpen is deprecated. Use Obs.")>]
module Ops_obsolete = 
    open Ops