Just to update this for anyone else that lands here. The upgrade steps (reproduced below) do apparently work:
apt-get -y install build-essential python-dev libffi-dev
service monit stop
service mopidy stop
pip install requests[security]
pip install --upgrade pip
pip install mopidy==1.1.2
pip install mopidy-spotify==2.3.1
pip install mopidy-dirble==1.3.0
service mopidy restart
service monit start