Implements remove user API (#42)

* Implementation of RemoveUser from madmin

* Added removeUser structure.

* Added removeUserResponse actions

* Added delete API to swagger

* Added tests to removeUser functions

* Removed extra space at EOF

* Changed context to be a parameter in admin_users functions

Co-authored-by: Benjamin Perez <benjamin@bexsoft.net>

swagger.yml

@@ -228,6 +228,24 @@ paths:
             $ref: "#/definitions/error"
       tags:
         - AdminAPI
+  /users/{name}:
+    delete:
+      summary: Remove user
+      operationId: RemoveUser
+      parameters:
+        - name: name
+          in: path
+          required: true
+          type: string
+      responses:
+        204:
+          description: A successful response.
+        default:
+          description: Generic error response.
+          schema:
+            $ref: "#/definitions/error"
+      tags:
+        - AdminAPI
   /groups:
     get:
       summary: List Groups