Prepare 5.2.1 (Alamofire#3208)

* Version to 5.2.1.

* Update Jazzy docs.

Prepare 5.2.0 Release (Alamofire#3189)

* Version to 5.2.0.

* Update Jazzy docs.

Prepare 5.1 Release (Alamofire#3143)

* Version to 5.1.0.

* Update Jazzy docs.

* Add one item to the CHANGELOG.

Prepare 5.0.5 (Alamofire#3129)

* Version to 5.0.5.

* Update Jazzy docs.

Remove note about compact linker warning.

Prepare 5.0.3 (Alamofire#3111)

* Version to 5.0.3.

* Update Jazzy docs.

Prepare 5.0.2 (Alamofire#3078)

* Version to 5.0.2.

* Update Jazzy docs.

Prepare 5.0.1 Release (Alamofire#3076)

* Version to 5.0.1.

* Update Jazzy docs.

Prepare 5.0 Release! (Alamofire#3064)

* Version to 5.0.

* Update Jazzy docs.

* Test stability.

Prepare 5.0.0-rc.3 (Alamofire#2988)

* Version to 5.0.0-rc.3.

* Update Jazzy docs.