Correct error message relative to API key (#13)

• Correct a typo in the error message thrown when
no key is specified (speicied ---> specified).

• Change the tense used in this message to make it
consistent with the rest of the file (present ---> past).

plugins/module_utils/vultr.py

@@ -73,7 +73,7 @@ def __init__(self, module, namespace):
                                "Error was %s" % (self.module.params.get('api_account'), to_native(e)))
 
         if not self.api_config.get('api_key'):
-            self.module.fail_json(msg="The API key is not speicied. Please refer to the documentation.")
+            self.module.fail_json(msg="No API key was specified. Please refer to the documentation.")
 
         # Common vultr returns
         self.result['vultr_api'] = {