fix slo test

Signed-off-by: Sylvain Hellegouarch <sh@defuze.org>

Author: Lawouach

CHANGELOG.md

@@ -2,11 +2,15 @@
 
 ## [Unreleased][]
 
+[Unreleased]: https://github.com/chaostoolkit-incubator/chaostoolkit-datadog/compare/0.1.1...HEAD
+
 ### Added
 
 * Metrics probe `chaosdatadog.metrics.get_metrics_state`
 
-[Unreleased]: https://github.com/chaostoolkit-incubator/chaostoolkit-datadog/compare/0.1.1...HEAD
+### Fixed
+
+* SLO test
 
 ## [0.1.1][]
 

tests/test_probes.py

@@ -9,6 +9,9 @@
 def test_get_slo(rest):
     r = MagicMock()
     r.getheader.return_value = None
+    r.headers = {
+        "Content-Type": "application/json"
+    }
     r.data = json.dumps({}).encode("utf-8")
     cl = MagicMock()
     cl.request.return_value = r