FAIL: Test some trivial edge cases for savgol_filter()

[rgommers]

OS X 10.8, MacPorts, reported by @cdeil:

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FAIL: Test some trivial edge cases for savgol_filter().
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Traceback (most recent call last):
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/nose/case.py", line 198, in runTest
self.test(*self.arg)
File "/Users/deil/temp/2013-09-25/scipy33/scipy/signal/tests/test_savitzky_golay.py", line 155, in test_sg_filter_trivial
assert_equal(y, [1.0])
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/numpy/testing/utils.py", line 257, in assert_equal
return assert_array_equal(actual, desired, err_msg, verbose)
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/numpy/testing/utils.py", line 719, in assert_array_equal
verbose=verbose, header='Arrays are not equal')
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/numpy/testing/utils.py", line 645, in assert_array_compare
raise AssertionError(msg)
AssertionError:
Arrays are not equal

(mismatch 100.0%)
x: array([ 1.])
y: array([ 1.])

Floating point numbers should not be compared equal. Will send a fix now.