Release v5.5.0

Release 5.3.0

Merge pull request #291 from omise/develop

[Dev -> Master] v5.2.0 (White-label installments)

Merge pull request #290 from omise/fix/v5.1_Readme

Update 3DS Authorizing Payment section in Readme

Merge pull request #277 from omise/feature/v5_refactoring

Release V5.0.0

Merge pull request #270 from omise/fix/MIT-2250_v4

Citi Points payment method doesn't have icon (v4.27.1)

Merge pull request #264 from omise/bump/v4.27.0

Bump version to v4.27.0

Merge pull request #249 from omise/develop

[Dev -> Master] 4.26.0