Merge branch 'hotfix-header-include' into 'master'

Remove faulty header include

See merge request !67

dune/dorie/solver/util_grid_creator.hh

@@ -5,7 +5,6 @@
 #include <array>
 #include <vector>
 #include <iostream>
-#include <stream>
 #include <type_traits>
 
 #include <dune/common/timer.hh>

testing/test-mass-conservation.cc

@@ -3,6 +3,16 @@
   #include "config.h"
 #endif
 
+#include <string>
+#include <iostream>
+
+#include <dune/common/parametertree.hh>
+#include <dune/common/parametertreeparser.hh>
+#include <dune/common/parallel/mpihelper.hh>
+
+#include <dune/grid/yaspgrid.hh>
+#include <dune/grid/uggrid.hh>
+
 #include <dune/dorie/test/test-mass-conservation.hh>
 
 namespace Dune{