Mux64 developments

Different changes implemented to allow for a configuration input for mux64 chip:

• Modified tamalero/ReadoutBoard.py to read voltages from mux64 for a given configuration
  • Also added a function to monitor the voltage of selected inputs for a given period of time
• Modified tamalero/utils.py to update config structure accounting for mux64 inputs
• Modified test_tamalero.py to include mux64 as an option
• Added working mux64 configuration file: mux64_v2.yaml
• Enable dashboard monitoring