Add example app

[sodre]

The goal of this PR is to add an example usage app for zeroae-goblet

Assuming you have checked out zeroae-goblet and pip installed -e here is what comes next

In terminal 1, start the Smee client smee -l DEBUG -P /events and click on the Smee link to see the events that GitHub is sending.

In terminal 2:

# Start the chalice app
export WEBHOOK_PROXY_URL=<from terminal 1>
chalice --local 

[codecov]

Codecov Report

Merging #14 into master will increase coverage by 0.15%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #14      +/-   ##
==========================================
+ Coverage   94.28%   94.44%   +0.15%     
==========================================
  Files           2        2              
  Lines          35       36       +1     
==========================================
+ Hits           33       34       +1     
  Misses          2        2              

Impacted Files	Coverage Δ
tests/smee/__init__.py	93.93% <ø> (+0.18%)	⬆️

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[sodre]

Here is an overview of what got changed by this pull request:

Complexity increasing per file
==============================
- examples/chalice/app.py  1
         

See the complete overview on Codacy