(partnership formation case; case arose primarily due to petitioner's failure to report W-2 wages; petitioner claims partnership existence so as to broker tax liability with partner; federal, not state, law controls classification of "partners" and "partnerships" for federal tax purposes; hallmark of partnership existence is two or more persons carrying on a business and divide the profits; no written agreement; while "partner" could sign checks he never testified; petitioner's recordkeeping poor to non-existent; court unable to tell what petitioner contributed or what "partner" contributed, and petitioner admitted to changing dates on various receipts provided to IRS so testimony not credible; petitioner failed to prove partnership existence).