Optimize coordinate transforms

[uppittu11]

Describe the behavior you would like added to mBuild
It seems that the coordinate transforms module can be made a little faster by using vectorization and eliminating unnecessary calculations. This becomes more important when dealing with large compounds.

Describe the solution you'd like

1. remove the unnecessary Tinv calculation
   

   mbuild/mbuild/coordinate_transform.py

   Line 70 in 8bc9234

   self.Tinv = inv(T)

2. vectorize the creation of transform matrices

3. parallelize the application of coordinate transforms for large objects