Functions that depend on `wma` don't work with `Float32` arrays

[kpa28-git]

Indicators.hma(Float64.(.1:.1:10.0)) works, but Indicators.hma(Float32.(.1:.1:10.0)) throws a dispatch error when it calls wma.

I think this is because the wma is defined, both the input and weight array are of type T<:Real. By default wma's weight array will be a Float64 array, forcing the input array to also be Float64. With financial data we might sometimes want to work with Float32 or other real number types.

I think it is as simple as changing this:
function wma(x::AbstractArray{T}; n::Int64=10, wts::AbstractArray{T}=collect(1:n)/sum(1:n)) where {T<:Real}

to this:
function wma(x::AbstractArray{T}; n::Int64=10, wts::AbstractArray{W}=collect(1:n)/sum(1:n)) where {T<:Real, W<:Real}

which would allow x to be a type different from wts.

[GHTaarn]

I just made #55 which will probably fix your issue as well