Expand log(Pow) when exponent is in (-1, 1]
Expand log(Pow) when exponent is in (-1, 1]

Enabled log expansion when argument is Pow and its exponent is in (-1,
1].
Complex logarithm of power can be expanded when exponent is in (-1, 1]
since it cannot get outside principal branch.

kaushik94/sympy,kaushik94/sympy,kaushik94/sympy