Allow v8 to allocate more heap

Prevent out-of-memory errors encountered during `lerna bootstrap` on
certain systems by allowing Node's v8 engine to allocate more heap.  The
default, even on 64-bit architectures, is too small (1.4GB) to
complete compilation successfully, so we set it to 4GB for the bootstrap
phase.

install.sh

@@ -10,4 +10,4 @@ export PATH=node_modules/.bin:$PATH
 
 echo "============================================================================================="
 echo "bootstrapping..."
-lerna bootstrap --reject-cycles
+env NODE_OPTIONS="--max-old-space-size=4096" lerna bootstrap --reject-cycles