Add -c conda-forge installation instructions

README.md

@@ -73,15 +73,15 @@ More information on conda environments can be found [here](https://conda.io/docs
 
 To install the precompiled Topaz package and its dependencies, including pytorch:
 ```
-conda install topaz -c tbepler -c pytorch
+conda install topaz -c tbepler -c pytorch -c conda-forge
 ```
 This installs pytorch from the official channel. To install pytorch for specific cuda versions, you will need to add the 'cudatoolkit=X.X' package. E.g. to install pytorch for CUDA 9.0:
 ```
 conda install cudatoolkit=9.0 -c pytorch
 ```
 or combined into a single command:
 ```
-conda install topaz cudatoolkit=9.0 -c tbepler -c pytorch
+conda install topaz cudatoolkit=9.0 -c tbepler -c pytorch -c conda-forge
 ```
 See [here](https://pytorch.org/get-started/locally/) for additional pytorch installation instructions.