Updated power test schematic
Based on feedback from Kevin, added a pullup resistor to !PWR_INT and
decoupling caps to the LDO providing VCC.
Also changed the ground signal on the gas gauge LDO from GND to
BATT_GND. Kevin pointed out that having BATT_GND as the ground for the
gas gauge would cause VSS to fluctuate with respect to SNS based on
load, which would confuse the current measurement. However, changing VSS
seems from the datasheet like it will prevent the sense resistor from
having the correct current through it. The datasheet says nothing to
indicate that the ground on the input LDO can't be BATT_GND. (It
actually might prefer that to be the case.) So I changed ground on the
input LDO to BATT_GND. This should keep the gas gauge's voltage
references stable with respect to the current under measurement.