Update Cuda

[mikemhenry]

Supersedes #214

[mikemhenry]

  openmm-7.8-py38_cuda102_1: Unsatisfiable dependencies for platform linux-64: {"__glibc[version='>=2.17,<3.0.a0']"}
  openmm-7.8-py38_cuda102_debug_1: Unsatisfiable dependencies for platform linux-64: {"__glibc[version='>=2.17,<3.0.a0']"}

will have to lookup how to fix this, I've seen it before

[mikemhenry]

Grumble, looks like - sysroot_linux-64 2.17 # [linux64] is what I normally do...