Fix KeyError when getting the Content-Type

Unfortunately, there isn't a good way to add a test for this as mocket
always adds the Content-Type header.

Author: oschwald

HISTORY.rst

@@ -3,6 +3,12 @@
 History
 -------
 
+2.7.1 (2022-03-29)
+++++++++++++++++++
+
+* Fixed ``KeyError`` when using the ``report()`` method. Reported by siang.
+  GitHub #99.
+
 2.7.0 (2022-03-28)
 ++++++++++++++++++
 

minfraud/webservice.py

@@ -618,7 +618,7 @@ def report(self, report: Dict[str, Optional[str]], validate: bool = True) -> Non
 
         response = self._do_request(uri, prepared_request)
         status = response.status_code
-        content_type = response.headers["Content-Type"]
+        content_type = response.headers.get("Content-Type")
         raw_body = response.text
         if status != 204:
             raise self._exception_for_error(status, content_type, raw_body, uri)
@@ -636,7 +636,7 @@ def _response_for(
 
         response = self._do_request(uri, prepared_request)
         status = response.status_code
-        content_type = response.headers["Content-Type"]
+        content_type = response.headers.get("Content-Type")
         raw_body = response.text
         if status != 200:
             raise self._exception_for_error(status, content_type, raw_body, uri)