setup.py has invalid syntax when using underscore 1.7.0

[stuartf]

[slapchop] Complete
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/fabric/main.py", line 743, in main
    *args, **kwargs
  File "/usr/lib/python2.7/dist-packages/fabric/tasks.py", line 405, in execute
    results['<local-only>'] = task.run(*args, **new_kwargs)
  File "/usr/lib/python2.7/dist-packages/fabric/tasks.py", line 171, in run
    return self.wrapped(*args, **kwargs)
  File "/home/stuart/src/oae-provisioning/fabfile/__init__.py", line 16, in ulous
    slapchop.fabric_setup(environment=environment)
  File "/usr/lib/python2.7/dist-packages/fabric/tasks.py", line 168, in __call__
    return self.run(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/fabric/tasks.py", line 171, in run
    return self.wrapped(*args, **kwargs)
  File "/home/stuart/src/oae-provisioning/fabfile/slapchop/__init__.py", line 19, in fabric_setup
    setup = imp.load_source('setup', 'fabfile/setup.py')
  File "fabfile/setup.py", line 1
    function (data) {
                    ^
SyntaxError: invalid syntax

#1 works around this by pinning underscore at 1.6.0, but we should fix the actual issue.

[jdalton]

Related to jashkenas/underscore#1805.