Python 2 syntax in aws-shell code

Hi,

I've `pip install aws-shell` today on python 3.7. When I hit `winpty aws-shell` in git bash on Windows 10, the `aws> ` prompt appears; everything looks fine. After running `configure` I get a traceback indicating python 2 syntax (print statement) has been used in the aws-shell code:

```
aws> configure
Traceback (most recent call last):
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\Scripts\aws-script.py", line 11, in

load_entry_point('aws==0.2.5', 'console_scripts', 'aws')()
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\lib\site-packages\pkg_resources\__i
nit__.py", line 489, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\lib\site-packages\pkg_resources\__i
nit__.py", line 2793, in load_entry_point
return ep.load()
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\lib\site-packages\pkg_resources\__i
nit__.py", line 2411, in load
return self.resolve()
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\lib\site-packages\pkg_resources\__i
nit__.py", line 2417, in resolve
module = __import__(self.module_name, fromlist=['__name__'], level=0)
File "C:\Users\i506278\AppData\Local\Continuum\miniconda3\envs\aws\lib\site-packages\aws\main.py", lin
e 23
print '%(name)s: %(endpoint)s' % {
^
SyntaxError: invalid syntax
```