v1.2.3

This update includes some database migrations -- run django manage.py migrate after updating.

Major updates

• 4397d4a, 243b9ef, 60b20e8: Added temperature tracking. (#53)
• 3ba58c9, c45e8ef: Added "Feeding Amounts" report. (#68)
• 37e7f8c, f07d6c2, 50a9243, 1d1b994: Added German translations. (thanks, @cephos and @mtonnie!)

Minor updates

• 4c1b333: Added languages info to README.
• 88dfe80: Added Python 3.7 target to Travis.
• c8611fa: Specified Python runtime for Heroku.
• bff17dd, 2f8bc83: Added support for two output formats from plotly.plot.
• f270af8: Added "Fortified brest milk" feeding type option (#71).