Backs out use of variables in Travis InstallBuilder installation script (#119)
Backs out use of variables in Travis InstallBuilder installation script (#119)

In the 6.2.0 release, these variables were not read properly, causing the installers not to be created as part of the tag build in Travis CI.
TexasDigitalLibrary/duracloud,duracloud/duracloud,duracloud/duracloud,TexasDigitalLibrary/duracloud,TexasDigitalLibrary/duracloud,duracloud/duracloud