Wrong output from lngamma

[wandonye]

The approximation for lngamma(9.0) is not 10.64917311666183

According to wolframalpha
https://www.wolframalpha.com/input/?i=lngamma%289.0%29
the right approximation should be
gammaln(9.0) = 10.60460290274525

This is due to a bug in this line:

GammaFn/Sources/GammaFn/Double+logForGamma.swift

Line 15 in 09d2a29

for i in (0..<Array.pLn.count - 1).reversed() {

for i in (0..<Array.pLn.count - 1).reversed() {

should be

for i in (1..<Array.pLn.count ).reversed() {