Improved docs on 5.15 context management
Improved docs on 5.15 context management

johansteffner/raven-python,akalipetis/raven-python,getsentry/raven-python,getsentry/raven-python,akalipetis/raven-python,getsentry/raven-python,akalipetis/raven-python,johansteffner/raven-python,johansteffner/raven-python