Cosmetic Changes + Hiding Admin Link when not signed in

...java/edu/drexel/TrainDemo/models/sales/PayPalPayment.java

src/main/resources/static/css/style.css

src/main/resources/static/js/search.js

src/main/resources/templates/admin/dashboard.html

src/main/resources/templates/admin/groups.html

src/main/resources/templates/admin/users.html

src/main/resources/templates/base.html

src/main/resources/templates/index.html

src/main/resources/templates/search.html

src/main/resources/templates/user/dashboard.html