Removes YAML body_format option

It would require adding a dependency to the YAML module while it might
not provide much benefit (has anybody seen a HTTP API taking YAML as
input ?)

lib/ansible/modules/network/basics/uri.py

@@ -66,7 +66,7 @@ options:
     default: null
   body_format:
     description:
-      - The serialization format of the body. Either raw, json, or yaml. When set to json or yaml, encodes the body argument and automatically sets the Content-Type header accordingly.
+      - The serialization format of the body. Either raw, or json. When set to json, encodes the body argument and automatically sets the Content-Type header accordingly.
     required: false
     default: raw
   method:
@@ -340,7 +340,7 @@ def main():
             user = dict(required=False, default=None),
             password = dict(required=False, default=None),
             body = dict(required=False, default=None),
-            body_format = dict(required=False, default='raw', choices=['raw', 'json', 'yaml']),
+            body_format = dict(required=False, default='raw', choices=['raw', 'json']),
             method = dict(required=False, default='GET', choices=['GET', 'POST', 'PUT', 'HEAD', 'DELETE', 'OPTIONS', 'PATCH']),
             return_content = dict(required=False, default='no', type='bool'),
             force_basic_auth = dict(required=False, default='no', type='bool'),
@@ -376,13 +376,10 @@ def main():
 
     dict_headers = {}
 
-    # If body_format is json or yaml, encore the body (wich can be a dict or a list) and automatically sets the Content-Type header
+    # If body_format is json, encodes the body (wich can be a dict or a list) and automatically sets the Content-Type header
     if body_format == 'json':
         body = json.dumps(body)
         dict_headers['Content-Type'] = 'application/json'
-    elif body_format == 'yaml':
-        body = yaml.dump(body)
-        dict_headers['Content-Type'] = 'application/yaml'
 
 
     # Grab all the http headers. Need this hack since passing multi-values is currently a bit ugly. (e.g. headers='{"Content-Type":"application/json"}')