maven proxy settings specified to node in zeppelin-web build do not carry over to bower or grunt as called in the postinstall script in package.json.
successful build – maven proxy settings are pushed down to all subsequent commands in the build script
failed build – maven proxy settings are passed to node install but not carried to postinstall actions
1) for bower, add proxy config to ~/.bowerrc setting proxy and https-proxy
2) for grunt, export HTTP_PROXY environment variable before calling mvn