I get the following error whenever I try to run conda install tensorflow
You have to run the conda info tensorflow and conda info numba to see each dependencies for each package and then you have to install those package like conda install package=version to fix the problem.
This is the error : 
Solving environment: failed
UnsatisfiableError: The following specifications were found to be in conflict:
  - numba -> numpy[version='>=1.14,<1.15.0a0']
  - tensorflow
Use "conda info " to see the dependencies for each package.