Pin tornado to >=4.5.3,<5 for now
Pin tornado to >=4.5.3,<5 for now

There appears to be a memory leak issue with tornado 5.x as reported in #2585

foosel/OctoPrint,Jaesin/OctoPrint,Jaesin/OctoPrint,foosel/OctoPrint,Jaesin/OctoPrint,foosel/OctoPrint,foosel/OctoPrint,Jaesin/OctoPrint