Repository: CodeForPhilly/chime (python)

Issue:
defaults.py AttributeError: __repr__ references self.region.s 
It looks like the `__repr__` function in `defaults.py` is referencing an attribute that no longer exists. Steps to reproduce below. Likely fix is just refactoring the return to use `self.region.susceptible` instead of `self.region.s`

```
from src.penn_chime.defaults import Constants, Regions, RateLos
delaware = 564696
chester = 519293
montgomery = 826075
bucks = 628341
philly = 1581000
DEFAULTS = Constants(
    # EDIT YOUR DEFAULTS HERE
    region=Regions(
        delaware=delaware,
        chester=chester,
        montgomery=montgomery,
        bucks=bucks,
        philly=philly),
    current_hospitalized=6,
    doubling_time=6,
    known_infected=157,
    n_days=60,
    market_share=0.15,
    relative_contact_rate=0,
    hospitalized=RateLos(0.05, 7),
    icu=RateLos(0.02, 9),
    ventilated=RateLos(0.01, 10),
)
DEFAULTS
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/IPython/core/formatters.py", line 224, in catch_format_error
    r = method(self, *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/IPython/core/formatters.py", line 702, in __call__
    printer.pretty(obj)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/IPython/lib/pretty.py", line 394, in pretty
    return _repr_pprint(obj, self, cycle)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/IPython/lib/pretty.py", line 684, in _repr_pprint
    output = repr(obj)
  File "/Users/pjhoberman/Projects/chime/src/penn_chime/defaults.py", line 56, in __repr__
    return f"Constants(susceptible_default: {self.region.s}, known_infected: {self.known_infected})"
AttributeError: 'Regions' object has no attribute 's'
Out[5]: In[6]: DEFAULTS.n_days
Out[6]: 60
DEFAULTS.known_infected
Out[7]: 157
```

Pull request description:
Fix Defaults.__repr__
Closes #173 

Patch:
diff --git a/src/penn_chime/defaults.py b/src/penn_chime/defaults.py
index e9d2ee9..ade9bc3 100644
--- a/src/penn_chime/defaults.py
+++ b/src/penn_chime/defaults.py
@@ -53,5 +53,5 @@ class Constants:
         self.n_days = n_days
 
     def __repr__(self) -> str:
-        return f"Constants(susceptible_default: {self.region.s}, known_infected: {self.known_infected})"
+        return f"Constants(susceptible_default: {self.region.susceptible}, known_infected: {self.known_infected})"
 


Test patch:
diff --git a/src/test_app.py b/src/test_app.py
index 181b3e3..82cec98 100644
--- a/src/test_app.py
+++ b/src/test_app.py
@@ -5,6 +5,7 @@ import pandas as pd
 from app import (projection_admits, alt)
 from penn_chime.models import sir, sim_sir, sim_sir_df
 from penn_chime.presentation import display_header, new_admissions_chart
+from penn_chime.settings import DEFAULTS
 
 
 # set up
@@ -66,6 +67,13 @@ def test_header_fail():
     st.cleanup()
 
 
+def test_defaultS_repr():
+    """
+    Test DEFAULTS.repr
+    """
+    repr(DEFAULTS)
+
+
 # Test the math
 
 def test_sir():