BLD: fix compiler paths for conda package test.

When `test_installed=true` the scons `prefix` path specifies where
is the tested diffpy library.  However, it is still necessary to
set CPATH, LIBRARY_PATH so that boost is found in the configure
step.

Author: pavoljuhas

conda-recipe/run_test.sh

@@ -1,5 +1,8 @@
 #!/bin/bash
 
+export CPATH="${PREFIX}/include:${CPATH}"
+export LIBRARY_PATH="${PREFIX}/lib:${LIBRARY_PATH}"
+
 MYNCPU=$(( (CPU_COUNT > 8) ? 8 : CPU_COUNT ))
 
 # Apply sconscript.local customizations.