Tag release ~π

Tag release 3.1.3

Merge pull request EasyPost#99 from EasyPost/bump_3.1.2

bump version to 3.1.2

Merge pull request EasyPost#97 from EasyPost/bump_3.1.1

bump version to 3.1.1

Merge pull request EasyPost#94 from EasyPost/bump_version_3.1.0

bump version to 3.1.0

Tag release 3.0.1

Merge pull request EasyPost#70 from EasyPost/tlsv1_2

Enforce TLSv1.2

Version 2.1.7

Version 2.1.6

Version 2.1.5