Update change_history.txt
Update change_history.txt

Added new change history for 1.0.7 and 1.0.8
rprobinson/MediPi,Samuel789/MediPi,Samuel789/MediPi,Samuel789/MediPi,rprobinson/MediPi,rprobinson/MediPi,Samuel789/MediPi,Samuel789/MediPi,rprobinson/MediPi,rprobinson/MediPi,rprobinson/MediPi,Samuel789/MediPi,Samuel789/MediPi,rprobinson/MediPi