Add nvm_is_iojs_version

test/fast/Unit tests/nvm_is_iojs_version

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+nvm_is_iojs_version 'iojs-' || die '"nvm_is_iojs_version iojs- was not true'
+nvm_is_iojs_version 'iojs-foo' || die '"nvm_is_iojs_version iojs- was not true'
+! nvm_is_iojs_version 'iojs' || die '"nvm_is_iojs_version iojs was not false'
+! nvm_is_iojs_version 'v1.0.0' || die '"nvm_is_iojs_version v1.0.0" was not false'