python2.6 incompatibility:  assertIsInstance and co
just got those

```
======================================================================
ERROR: test_banklist_header (pandas.io.tests.test_html.TestReadHtmlBase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/buildd/pandas-0.12.0/debian/tmp/usr/lib/python2.6/dist-packages/pandas/io/tests/test_html.py", line 387, in test_banklist_header
    self.assertTupleEqual(df.shape, ground_truth.shape)
AttributeError: 'TestReadHtmlBase' object has no attribute 'assertTupleEqual'

======================================================================
ERROR: test_banklist_no_match (pandas.io.tests.test_html.TestReadHtmlBase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/buildd/pandas-0.12.0/debian/tmp/usr/lib/python2.6/dist-packages/pandas/io/tests/test_html.py", line 164, in test_banklist_no_match
    self.assertIsInstance(df, DataFrame)
AttributeError: 'TestReadHtmlBase' object has no attribute 'assertIsInstance'

======================================================================
ERROR: test_gold_canyon (pandas.io.tests.test_html.TestReadHtmlBase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/buildd/pandas-0.12.0/debian/tmp/usr/lib/python2.6/dist-packages/pandas/io/tests/test_html.py", line 418, in test_gold_canyon
    self.assertIn(gc, df.to_string())
AttributeError: 'TestReadHtmlBase' object has no attribute 'assertIn'

```

there are more points where used... if python2.6 is no longer supported that is ok too ;)
