Do more casting for the bilinear basis
Do more casting for the bilinear basis

Integer, rational and float are all common types for the gap so we
should convert them to MPFR. Now that we are not doing Cholesky with a
separate library, we have to worry more about this.

Signed-off-by: Connor Behan <89f96a099c47edae2e9c5a371cbf43991ac7aa8c@gmail.com>

cbehan/pycftboot