Add nvm_has_system_iojs

test/fast/Unit tests/nvm_has_system_iojs

@@ -0,0 +1,31 @@
+#!/bin/sh
+
+cleanup () {
+  rm ../../../versions/io.js/v0.1.2/node
+  rm ../../../versions/io.js/v0.1.2/iojs
+  rmdir ../../../versions/io.js/v0.1.2
+}
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+mkdir ../../../versions/io.js/v0.1.2
+touch ../../../versions/io.js/v0.1.2/node
+touch ../../../versions/io.js/v0.1.2/iojs
+
+nvm use iojs-v0.1.2
+
+if command -v iojs; then
+  nvm_has_system_iojs
+else
+  ! nvm_has_system_iojs
+fi
+
+nvm deactivate /dev/null 2>&1
+
+if command -v iojs; then
+  nvm_has_system_iojs
+else
+  ! nvm_has_system_iojs
+fi
+