Released v16.0.0

* Drop support for Python 2.6.
* Upgrade pip to 10.0.1.
* Upgrade setuptools to 39.1.0.
* Upgrade wheel to 0.31.1.

Released v15.1.0

* Support Python 3.6.
* Upgrade setuptools to 28.0.0.
* Upgrade pip to 9.0.1.
* Don't install pre-release versions of pip, setuptools, or wheel from PyPI.

Released v15.0.3

* Test for given python path actually being an executable *file*, :issue:`939`
* Only search for copy actual existing Tcl/Tk directories (:pull:`937`)
* Generically search for correct Tcl/Tk version (:pull:`926`, :pull:`933`)
* Upgrade setuptools to 22.0.5

Released v15.0.2

* Copy Tcl/Tk libs on Windows to allow them to run, fixes :issue:`93`
  (:pull:`888`)
* Upgrade setuptools to 21.2.1.
* Upgrade pip to 8.1.2.

Released v15.0.1

* Print error message when DEST_DIR exists and is a file
* Upgrade setuptools to 20.3
* Upgrade pip to 8.1.1.

Released v15.0.0

* Remove the `virtualenv-N.N` script from the package; this can no longer be correctly created from a wheel installation.
  Resolves :issue:`851`, :issue:`692`

* Remove accidental runtime dependency on pip by extracting certificate in the
  subprocess.

* Upgrade setuptools 20.2.2.

* Upgrade pip to 8.1.0.

Released v14.0.6

* Upgrade setuptools to 20.0
* Upgrade wheel to 0.29.0
* Fix an error where virtualenv didn't pass in a working ssl certificate for
  pip, causing "weird" errors related to ssl.

Released v14.0.5

* Homogenize drive letter casing for both prefixes and filenames. :issue:`858`

Released v14.0.4

* Upgrade setuptools to 19.6.2

* Revert ac4ea65; only correct drive letter case.
  Fixes :issue:`856`, :issue:`815`

Released v14.0.3

* Upgrade setuptools to 19.6.1