Error while installing V5

While installing V5 ,when i enter “bench init frappe-bench && cd frappe-bench” this command ,
i got following error

Already using interpreter /usr/bin/python
Cloning into 'frappe'...
installing frappe
Compiling /home/indictrans/frappe_five/frappe-bench/env/build/gunicorn/gunicorn/workers/_gaiohttp.py ...
  File "/home/indictrans/frappe_five/frappe-bench/env/build/gunicorn/gunicorn/workers/_gaiohttp.py", line 68
    yield from self.wsgi.close()
             ^
SyntaxError: invalid syntax
Compiling
 /home/indictrans/frappe_five/frappe-bench/env/build/selenium/selenium/test/selenium/webdriver/browser_specific_template.py
 ...
 File 
"/home/indictrans/frappe_five/frappe-bench/env/build/selenium/selenium/test/selenium/webdriver/browser_specific_template.py",
 line 21
 from selenium.##PACKAGE_NAME## import ##GENERAL_FILENAME##
                                                             ^
SyntaxError: invalid syntax

/bin/sh: 1: npm: not found
Traceback (most recent call last):
  File "/usr/local/bin/bench", line 9, in <module>
    load_entry_point('bench==0.92', 'console_scripts', 'bench')()
  File "/home/indictrans/frappe_five/bench-repo/bench/cli.py", line 56, in cli
    bench()
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 610, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 590, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 936, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 782, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 416, in invoke
    return callback(*args, **kwargs)
  File "/home/indictrans/frappe_five/bench-repo/bench/cli.py", line 161, in init
    no_auto_update=no_auto_update, frappe_path=frappe_path, frappe_branch=frappe_branch)
  File "/home/indictrans/frappe_five/bench-repo/bench/utils.py", line 80, in init
    setup_socketio(bench=path)
  File "/home/indictrans/frappe_five/bench-repo/bench/utils.py", line 108, in setup_socketio
    exec_cmd("npm install nodemon socket.io redis express superagent cookie", cwd=bench)