Remove MaterialModule. (#6803)

BREAKING CHANGE: MaterialModule has been removed and is no longer available.  As noted in the changelog for beta.3, an aggregate module like MaterialModule prevents tools from being able to treeshake unused components and modules.

Author: josephperrott

src/lib/module.ts

@@ -14,7 +14,6 @@
 
 export * from './version';
 export * from './core';
-export * from './module';
 
 export * from './autocomplete/index';
 export * from './button/index';