Remove dependency on Statistics and src/mean.jl (#255)

* remove dependency on Statistics

* remove src/mean.jl

Author: hyrodium

Project.toml

@@ -7,7 +7,6 @@ LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Quaternions = "94ee1d12-ae83-5a48-8b1c-48b8ff168ae0"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
-Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
 Quaternions = "0.5.3, 0.6, 0.7"

src/Rotations.jl

@@ -8,8 +8,6 @@ using StaticArrays
 using Random
 using Quaternions
 
-import Statistics
-
 include("util.jl")
 include("core_types.jl")
 include("unitquaternion.jl")