assert_almost_equal
Hi, I'm wondering if the following behavior of pandas._testing.assert_almost_equal is expected:
#### Code Sample, a copy-pastable example if possible

```
from pandas import _testing
_testing.assert_almost_equal(0.000011, 0.000012, check_less_precise=True)
```
#### Expected Output

Expect no output / no AssertionError
#### Actual Output

```
AssertionError                            Traceback (most recent call last)
<ipython-input-199-ace78e82c603> in <module>()
      1 from pandas import _testing
----> 2 _testing.assert_almost_equal(0.000011, 0.000012, check_less_precise=True)

pandas/src/testing.pyx in pandas._testing.assert_almost_equal (pandas/src/testing.c:3887)()

pandas/src/testing.pyx in pandas._testing.assert_almost_equal (pandas/src/testing.c:3653)()

AssertionError: expected 0.00001 but got 0.00001, with decimal 3
```

Note that the numbers differ at decimal 6 and the output suggests they are different at position 3. 
#### output of `pd.show_versions()`
## INSTALLED VERSIONS

commit: None
python: 2.7.11.final.0
python-bits: 64
OS: Darwin
OS-release: 15.5.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.18.1
nose: None
pip: 8.0.2
setuptools: 21.2.1
Cython: None
numpy: 1.11.0
scipy: 0.17.1
statsmodels: None
xarray: None
IPython: 4.2.0
sphinx: None
patsy: None
dateutil: 2.5.3
pytz: 2016.4
blosc: None
bottleneck: None
tables: None
numexpr: None
matplotlib: 1.5.1
openpyxl: 2.3.3
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.0.12
pymysql: None
psycopg2: 2.6.1 (dt dec pq3 ext lo64)
jinja2: 2.8
boto: 2.39.0
pandas_datareader: None
