Broken test for FRED

[femtotrader]

https://travis-ci.org/pydata/pandas-datareader/jobs/148725878

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FAIL: test_fred (pandas_datareader.tests.test_fred.TestFred)
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Traceback (most recent call last):
  File "/home/travis/build/pydata/pandas-datareader/pandas_datareader/tests/test_fred.py", line 30, in test_fred
    self.assertEqual(int(received), 16440)
AssertionError: 16475 != 16440
-------------------- >> begin captured logging << --------------------
requests.packages.urllib3.connectionpool: INFO: Starting new HTTP connection (1): research.stlouisfed.org
requests.packages.urllib3.connectionpool: DEBUG: "GET /fred2/series/GDP/downloaddata/GDP.csv HTTP/1.1" 301 267
requests.packages.urllib3.connectionpool: INFO: Starting new HTTPS connection (1): fred.stlouisfed.org
requests.packages.urllib3.connectionpool: DEBUG: "GET /series/GDP/downloaddata/GDP.csv HTTP/1.1" 200 1603
--------------------- >> end captured logging << ---------------------