TST: add tests for caosdb-server#183

Tests for caosdb-server#183 (closed), see caosdb-server!37 (merged)

tests/test_issues_server.py

@@ -450,4 +450,4 @@ def test_issue_183():
         db.Property(name="TestDateTime2", datatype=db.DATETIME,
                     value="2015-05-05T20:15").insert()
     assert cm.value.errors[0].msg == ("Cannot parse value to datetime format "
-        "(yyyy-mm-dd'T'hh:mm:ss[.fffffffff][TimeZone]).")
+                                      "(yyyy-mm-dd'T'hh:mm:ss[.fffffffff][TimeZone]).")