Removed 5.1.x upgrade steps
Removed 5.1.x upgrade steps

nvisionative/Dnn.Platform,mitchelsellers/Dnn.Platform,valadas/Dnn.Platform,bdukes/Dnn.Platform,nvisionative/Dnn.Platform,mitchelsellers/Dnn.Platform,dnnsoftware/Dnn.Platform,dnnsoftware/Dnn.Platform,nvisionative/Dnn.Platform,bdukes/Dnn.Platform,bdukes/Dnn.Platform,dnnsoftware/Dnn.Platform,mitchelsellers/Dnn.Platform,valadas/Dnn.Platform,dnnsoftware/Dnn.Platform,mitchelsellers/Dnn.Platform,valadas/Dnn.Platform,valadas/Dnn.Platform,mitchelsellers/Dnn.Platform,valadas/Dnn.Platform,bdukes/Dnn.Platform,dnnsoftware/Dnn.Platform