fix: adding support to point to api gateway distribution

[praneetap]

Issue #, if available:
Found an issue where we don't support using the distribution supported by apigateway for custom domains.
Description of changes:

Description of how you validated changes:
validated end to end
Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Add/update example to examples/2016-10-31

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-io]

Codecov Report

Merging #1230 into develop will increase coverage by 0.05%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #1230      +/-   ##
===========================================
+ Coverage    94.43%   94.48%   +0.05%     
===========================================
  Files           72       72              
  Lines         3736     3735       -1     
  Branches       739      739              
===========================================
+ Hits          3528     3529       +1     
+ Misses         105      104       -1     
+ Partials       103      102       -1

Impacted Files	Coverage Δ
samtranslator/model/apigateway.py	97.89% <ø> (-0.02%)	⬇️
samtranslator/model/api/api_generator.py	95.22% <100%> (+0.56%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update dbc8f79...fbb7bdc. Read the comment docs.

[keetonian]

home is the base path and fetch is the api path, correct? That's what it looks like looking at the example template, just want to make sure I understand this.