Arizona Republic:  “The medical-marijuana era might have arrived in Arizona, but dispensaries are stuck doing business like street-level dealers: cash only.  Checking accounts and credit-card machines for state-licensed dispensaries have become casualties of a crossfire between state and federal laws. . . . banks and credit unions, which are federally insured, steer clear of Arizona’s new health buzz, citing federal regulators. Medical-marijuana proponents say banks also won’t lend to the marijuana industry out of fear of federal seizures.  The cash-only conundrum is a nightmare for dispensaries