bump version to v0.2.2

bump version to 0.2.1

bump version some more due to incompatible API changes. Fixes octokit…

…#158

bump version to 0.1.17

Bump version to 0.1.16

bump version to v0.1.15

bump version to 0.1.14

bump version

bump version number.

Added option to API calls to allow request headers to be sent with HT…

…TP requests. Fixes octokit#80. Fixes octokit#97.