Reduce file volume

[mkelley]

No need for float64 and int64 in the FITS files:

No.    Name      Ver    Type      Cards   Dimensions   Format
  0  SCI           1 PrimaryHDU     291   (1185, 1186)   float32   
  1  MASK          1 ImageHDU       208   (1185, 1186)   int16   
  2  PSF           1 ImageHDU        11   (23, 23)   float32   
  3  REF           1 ImageHDU        89   (1201, 1201)   float32   
  4  SANGLE        1 ImageHDU        23   (1200, 1200)   float64   
  5  SANGLEMASK    1 ImageHDU        23   (1200, 1200)   int64   
  6  SANGLEREF     1 ImageHDU        23   (1200, 1200)   float64