Update sinatra gem (#905)
Update sinatra gem (#905)

CircleCI detected a vulnerability using sinatra 2.0.1. This commit
updates it to 2.0.3 using the command `bundle update sinatra`.
cartothemax/ifme,julianguyen/ifme,julianguyen/ifme,cartothemax/ifme,julianguyen/ifme,cartothemax/ifme,julianguyen/ifme,cartothemax/ifme