add set around viewkeys

[jihoonl]

To fix

2016-10-13 11:27:50,699 INFO rospy.topics topicmanager initialized
2016-10-13 11:27:51,008 INFO marv._node Registered nodes in order: ['fileset', u'md5', u'bagset_name', u'bagmeta', u'messages', u'camera_frames', u'diag_count', u'fulltext']
2016-10-13 11:27:51,011 WARNING marv._site Unused config sections ['marv']
Traceback (most recent call last):
  File "/home/jihoonl/tools/marv/venv/bin/marv", line 9, in <module>
    load_entry_point('marv-server==2.0.0b1', 'console_scripts', 'marv')()
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/marv/cli.py", line 343, in cli
    marv(auto_envvar_prefix='MARV')
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/jihoonl/tools/marv/venv/local/lib/python2.7/site-packages/marv/cli.py", line 259, in marv_node_run
    unknown = set(node) - app.site.nodes.nodes.viewkeys()
TypeError: unsupported operand type(s) for -: 'set' and 'KeysView'
2016-10-13 11:27:51,012 INFO rospy.core signal_shutdown [atexit]

[chaoflow]

Which version of Python are you using?

[jihoonl]

I'm using 2.7.6

[chaoflow]

@jihoonl In Python 2.7.6 KeysViews and sets were not yet compatible. Beyond that there are many more issues with 2.7.6. We updated the installation instructions to get the latest Python 2.7 on trusty.

Does this work for you?

[jihoonl]

the instruction should work thanks!