Fixed bugs in newly added CustomLennardJonesFluidMixed, which attempts to mix NonbondedForce and CustomNonbondedForce.
Modified CustomLennardJonesFluidMixture so that half of particles are CustomNonbondedForce and other half are NonbondedForce.
Added test to make sure system could be serialized and deserialized to produce the same energies and forces.
Merge remote-tracking branch 'upstream/master'
Merge pull request #129 from jchodera/master

Additional tests and bugfixes
Inital checkin of CI for repex
minor fixes
Added nose exclude
Try to fix pip
mpi4py
Skip slow test
Only testing testsystems for now.
rearrange travis
Reverted previous and trying new fix
Another attempt
Debug build recipe
OK, force conda to not install pip requirements during build
Removed pymbar from setup requirements
Remove nose from setup.py
Merge pull request #131 from choderalab/ci

[WIP] Inital checkin of CI for repex