nni installation failure when NODE_PATH exists or node<10.0.0 has installed

[QuanluZhang]

bug 1:
In my environment, NODE_PATH already exits, e.g., /usr/lib/nodejs:/usr/lib/node_modules:/usr/share/javascript. This induces the error below:
`

Cleaning

rm -rf /usr/lib/nodejs:/usr/lib/node_modules:/usr/share/javascript
rm -rf /tmp/nni-yarn
rm -rf /home/zhac/.local/nni/serve
mkdir -p /usr/lib/nodejs:/usr/lib/node_modules:/usr/share/javascript
mkdir: cannot create directory ‘/usr/lib/nodejs:’: Permission denied
Makefile:178: recipe for target 'install-dependencies' failed
make: *** [install-dependencies] Error 1
Traceback (most recent call last):
File "", line 1, in
File "/tmp/pip-req-build-r7w8srdk/setup.py", line 69, in
'install': CustomInstallCommand
File "/home/zhac/anaconda3/lib/python3.7/site-packages/setuptools/init.py", line 140, in setup
return distutils.core.setup(**attrs)
File "/home/zhac/anaconda3/lib/python3.7/distutils/core.py", line 148, in setup
dist.run_commands()
File "/home/zhac/anaconda3/lib/python3.7/distutils/dist.py", line 966, in run_commands
self.run_command(cmd)
File "/home/zhac/anaconda3/lib/python3.7/distutils/dist.py", line 985, in run_command
cmd_obj.run()
File "/home/zhac/anaconda3/lib/python3.7/site-packages/wheel/bdist_wheel.py", line 238, in run
self.run_command('install')
File "/home/zhac/anaconda3/lib/python3.7/distutils/cmd.py", line 313, in run_command
self.distribution.run_command(command)
File "/home/zhac/anaconda3/lib/python3.7/distutils/dist.py", line 985, in run_command
cmd_obj.run()
File "/tmp/pip-req-build-r7w8srdk/setup.py", line 34, in run
subprocess.run(['make', 'pip-install'], check=True)
File "/home/zhac/anaconda3/lib/python3.7/subprocess.py", line 468, in run
output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['make', 'pip-install']' returned non-zero exit status 2.
error
Failed building wheel for NNI
`
bug 2:
On the other hand, if node has already been installed on the machine, but its version is smaller than 10.0.0. Even though nni installation installs node larger than 10.0.0, it still uses the previous node.

[QuanluZhang]

resolved by #246

[HudsonHuang]

I meet this error and solve by running command:
node
And found node installed, so I uninstall it using:
sudo apt-get remove nodejs
and re-install NNI as guide again, problem solved.