1998 Sierra - Master Cylinder or Brake Line Leak?

I recently did some work on my truck because the brake pedal went to the floor. I replaced my master cylinder because there was some brake fluid leaking in that area and a friend told me that it was bad. I also ended up changing out one of the calipers because the seal was broken and leaking fluid. Over all I ended up changing out the front brakes, the passenger side caliper and rotor, and the master cylinder with a new reservoir. I have brakes now but I'm still getting a brake fluid leak around the area of the master cylinder possibly at the reservoir/cylinder connection. Is it another bad cylinder or do I have a brake line leak that I don't see?