Starter Certificate Template Revamp

This work revises the contents of default and verified base PDF templates (to be replaced per platform).

Here's a proof using the default new template - https://s3.amazonaws.com/verify-test.edx.org/downloads/747a4d0449624155a5b3933844867126/Certificate.pdf. Its not pretty, but the important message to the platform instance owners that the template needs to be replaced comes across.