MAINT: PEP8 + spelling fixes in testing.py
## [Current coverage](https://codecov.io/github/pydata/pandas?ref=7f8a90b7cb86d5f2d49f6cdb0c7ae9a23eda5ad8) is `88.64%`

> Merging **#12637** into **master** will not affect coverage as of [`7f8a90b`](https://codecov.io/github/pydata/pandas/commit/7f8a90b7cb86d5f2d49f6cdb0c7ae9a23eda5ad8)

``` diff
@@            master   #12637   diff @@
=======================================
  Files          275      275       
  Stmts       133688   133688       
  Branches         0        0       
  Methods          0        0       
=======================================
+ Hit         118511   118512     +1
  Partial          0        0       
+ Missed       15177    15176     -1
```

> Review entire [Coverage Diff](https://codecov.io/github/pydata/pandas/compare/f71537ab2561ab5727008095e9685966619fa7b9...7f8a90b7cb86d5f2d49f6cdb0c7ae9a23eda5ad8) as of [`7f8a90b`](https://codecov.io/github/pydata/pandas/commit/7f8a90b7cb86d5f2d49f6cdb0c7ae9a23eda5ad8)
> 
> Powered by [Codecov](https://codecov.io). Updated on successful CI builds.
 theres a flake directive at the top of the file, need to remove it
 Removed the directive as well as all of the `flake8` violations, and Travis gives the green light.  Should be good to merge.
 thanks!
