You may have inadvertently indicated that you had a plan that requires Form 1095-A. You can go back to the Health Insurance section and make sure you answered "No" under Were you covered by any of these plans in 2016? (Click the screenshot below for reference.) Once you change your answer to No and click Continue, you should no longer be prompted to enter 1095-A information.
You don't need your 1095-B to file your tax return, but you should store the form with your tax records.