add puttracesegments to boto whitelist avoid a catch 22

[kapilt]

Issue #, if available:
closes #207

Description of changes:
whitelist putting tracesegments to xray to avoid a catch 22 when the segment is closed.

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 #210 into master will decrease coverage by 0.06%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #210      +/-   ##
==========================================
- Coverage   84.45%   84.38%   -0.07%     
==========================================
  Files          78       78              
  Lines        3094     3094              
==========================================
- Hits         2613     2611       -2     
- Misses        481      483       +2     

Impacted Files	Coverage Δ
aws_xray_sdk/ext/botocore/patch.py	81.25% <0.00%> (ø)
aws_xray_sdk/core/sampling/local/reservoir.py	88.88% <0.00%> (-11.12%)	⬇️

---

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 96134f6...9bf68f6. Read the comment docs.