Removing remaining references to the projecthydra GitHub organization in the code base

[jrgriffiniii]

Resolves #1318

[coveralls]

Coverage remained the same at 89.551% when pulling afa5477 on jrgriffiniii:issues-1318-jrgriffiniii-gsub-projecthydra into 972d65b on samvera:master.

[coveralls]

Coverage remained the same at 89.551% when pulling afa5477 on jrgriffiniii:issues-1318-jrgriffiniii-gsub-projecthydra into 972d65b on samvera:master.

[botimer]

I tend to prefer separate commits for content and formatting, but this is all documentation, comments, and the like. I think it's fine to combine here.