#81 #102 When a user switches course sections that they already had, we delete them as subscribers to the previous section they had and add them as subscribers to the new one
#81 #102 When a user switches course sections that they already had, we delete them as subscribers to the previous section they had and add them as subscribers to the new one

mukulikadey/SOEN341-Group1,mukulikadey/SOEN341-Group1,mukulikadey/SOEN341-Group1,mukulikadey/SOEN341-Group1,mukulikadey/SOEN341-Group1,mukulikadey/SOEN341-Group1