Changed service keepAlive from POST to PUT

Fixed some very confusing log messages

Change-Id: I48679ba69252a09e610cdc239e2fb56554d665d9
Issue-ID: NONRTRIC-164
Signed-off-by: PatrikBuhr <patrik.buhr@est.tech>
diff --git a/policy-agent/docs/api.yaml b/policy-agent/docs/api.yaml
index 3ea913d..306b15a 100644
--- a/policy-agent/docs/api.yaml
+++ b/policy-agent/docs/api.yaml
@@ -135,7 +135,7 @@
           schema:
             type: string
         '423':
-          description: RIC is locked
+          description: RIC is not operational
           schema:
             type: string
       deprecated: false
@@ -170,7 +170,7 @@
           schema:
             type: string
         '423':
-          description: RIC is locked
+          description: RIC is not operational
           schema:
             type: string
       deprecated: false
@@ -342,7 +342,7 @@
         - name: managedElementId
           in: query
           description: managedElementId
-          required: false
+          required: true
           type: string
       responses:
         '200':
@@ -415,7 +415,7 @@
           schema:
             type: string
         '400':
-          description: Cannot parse the ServiceRegistrationInfo
+          description: The ServiceRegistrationInfo is not accepted
           schema:
             type: string
         '401':
@@ -487,11 +487,11 @@
             type: string
       deprecated: false
   /services/keepalive:
-    post:
+    put:
       tags:
         - Service registry and supervision
       summary: Heartbeat from a serice
-      operationId: keepAliveServiceUsingPOST
+      operationId: keepAliveServiceUsingPUT
       consumes:
         - application/json
       produces: