Formulate release 5.1.2.

Release 6.0.0 (intercom#261)

Merge pull request intercom#258 from intercom/conor/bump

Release version 5.1.1

Merge pull request intercom#256 from intercom/conor/bump

Bump version in package.json

Merge pull request intercom#247 from intercom/conor/release-5.0.2

Bump version to 5.0.2

Merge pull request intercom#241 from intercom/skylerwshaw/bump_5_0_1

Bump version to 5.0.1

Merge pull request intercom#237 from intercom/skylerwshaw/bump_to_v5

Bump version to 5.0.0

Merge pull request intercom#223 from intercom/conor/bump

Bump version to 4.1.2

Merge pull request intercom#221 from intercom/conor/update

Bump version to 4.1.1

Merge pull request intercom#216 from intercom/conor/fix-release

Fix release script