Added numpy to build requirements (for testing) and set OPENMM_PLUGIN_DIR to...

Added numpy to build requirements (for testing) and set OPENMM_PLUGIN_DIR to enable locating imports.

tools/conda-recipe/build.sh

@@ -43,6 +43,7 @@ cd python
 $PYTHON setup.py install
 
 # Run Python tests.
+export OPENMM_PLUGIN_DIR=$OPENMM_LIB_PATH/plugins
 nosetests -vv --processes=-1 --process-timeout=200
 
 # Remove one random file

tools/conda-recipe/meta.yaml

@@ -7,11 +7,14 @@ requirements:
     - cmake
     - python
     - fftw3f
+    # required for testing python install:
     - nose
+    - numpy
 
   run:
     - python
     - fftw3f
+    - numpy
 
 about:
   home: https://simtk.org/home/openmm