Add nvm_is_valid_version

test/fast/Unit tests/nvm_is_valid_version

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+nvm_is_valid_version 0.1.2 || die "nvm_is_valid_version 0.1.2 did not return 0"
+nvm_is_valid_version foo && die "nvm_is_valid_version foo did not return 1"
+nvm_is_valid_version iojs-1 || die "nvm_is_valid_version iojs-1 did not return 0"
+nvm_is_valid_version iojs || die "nvm_is_valid_version iojs did not return 0"
+nvm_is_valid_version node || die "nvm_is_valid_version node did not return 0"
+nvm_is_valid_version stable || die "nvm_is_valid_version stable did not return 0"
+nvm_is_valid_version unstable || die "nvm_is_valid_version unstable did not return 0"