You could try to install a specific NumPy version. In your case you could use:
$ conda install numpy=1.13
In case of conflicts it will show the conflicting packages.
For example:
$ conda install numpy=1.14
Solving environment: failed
UnsatisfiableError: The following specifications were found to be in conflict:
- blaze -> numba -> numpy[version='>=1.13,<1.14.0a0']
- numpy=1.14
Use "conda info <package>" to see the dependencies for each package.
In this case blaze and numba prevent NumPy from upgrading.
