An IRS technology official at the center of a House investigation into whether he pushed the agency to award contracts potentially worth up to $500 million to a company owned by a personal friend pleaded the Fifth Amendment and refused to testify at a House hearing Wednesday. A House Committee on Oversight and Government Reform report Tuesday said Greg Roseman, an IRS deputy director, may have influenced the IRS to award lucrative IT contracts to Strong Castle, Inc. The same report also said the company had given the Small Business Administration misleading information to win approval so it could obtain…