Rename \degree command to \academicdegree in thesis class

[mclosa8]

The umassthesis.cls template defines a \degree command for specifying the academic degree on the title page. This conflicts with the \degree macro provided by the gensymb package, which is used throughout the document for the angular degree symbol (°).

This PR renames the user-facing command from \degree to \academicdegree in the class file. The internal macros \@degree and \@degreeabbrv remain unchanged, so no other modifications to the template are required.

Usage:

% Before
\degree{Doctor of Philosophy}{Ph.D.}

% After
\academicdegree{Doctor of Philosophy}{Ph.D.}