changes APIHandler attribute "dump" to "header" for clarity

src/APIHandler.py

@@ -9,7 +9,7 @@ class APIHandler:
         '''Init method, apikey suggested but not required (empty by default).'''
         self.auth = {"Authorization" : apikey}
         self.content = {"Content-Type" : "application/json"}
-        self.dump = {**self.auth, **self.content}
+        self.header = {**self.auth, **self.content}
         self.elaburl = ELABFTW_API_URL
     def get_entry_from_elabid(self, elabid, entryType="items"):
         '''
@@ -18,7 +18,7 @@ class APIHandler:
         Entry type can be either "experiments" or "items".
         '''
         # TO-DO: validation and error handling on entryType value.
-        header = self.dump
+        header = self.header
         response = requests.get(
             headers = header,
             url = f"{self.elaburl}/{entryType}/{elabid}",