Sendgrid

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**Library - Fix**
- [PR 145](https://github.com/sendgrid/python-http-client/pull/145): update request exception logging and update tests. Thanks to [childish-sambino](https://github.com/childish-sambino)!

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**Library - Chore**
- [PR 143](https://github.com/sendgrid/python-http-client/pull/143): update GitHub branch references to use HEAD. Thanks to [thinkingserious](https://github.com/thinkingserious)!

**Library - Feature**
- [PR 123](https://github.com/sendgrid/python-http-client/pull/123): add API logging to client. Thanks to [tysonholub](https://github.com/tysonholub)!

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**Library - Fix**
- [PR 128](https://github.com/sendgrid/python-http-client/pull/128): Remove ResourceWarning on module import. Thanks to [connesy](https://github.com/connesy)!

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**Library - Chore**
- [PR 140](https://github.com/sendgrid/python-http-client/pull/140): add Python 3.8 to Travis. Thanks to [childish-sambino](https://github.com/childish-sambino)!

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**Library - Fix**
- [PR 132](https://github.com/sendgrid/python-http-client/pull/132): Exclude tests directory from package data. Thanks to [bwind](https://github.com/bwind)!

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**Library - Fix**
- [PR 138](https://github.com/sendgrid/python-http-client/pull/138): update pypi token to use environment variable. Thanks to [eshanholtz](https://github.com/eshanholtz)!