try fix travis

.travis.yml

@@ -1,6 +1,6 @@
 os: osx
-osx_image: xcode9
-language: generic
+osx_image: xcode9.1
+language: objective-c
 
 env:
   global:

scripts/env/installNode.sh

@@ -1,5 +1,3 @@
 #!/bin/bash -e
 
-curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.1/install.sh | bash
-export NVM_DIR="$HOME/.nvm" && [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"
 nvm install stable