Use 'PYEND' instead of '<<<' to terminate PYACTION and PYINPUT

tests/parser/EmbeddedPython.cpp

@@ -68,17 +68,17 @@ BOOST_AUTO_TEST_CASE(PYINPUT_BASIC) {
         PYINPUT
         kw = context.DeckKeyword( context.parser['FIELD'] )
         context.deck.add(kw)
-        <<<
+        PYEND
         DIMENS
         2 2 1 /
         PYINPUT
         import numpy as np
         dx = np.array([0.25, 0.25, 0.25, 0.25])
         active_unit_system = context.deck.active_unit_system()
-        default_unit_system = context.deck.default_unit_system()        
+        default_unit_system = context.deck.default_unit_system()
         kw = context.DeckKeyword( context.parser['DX'], dx, active_unit_system, default_unit_system )
         context.deck.add(kw)
-        <<<
+        PYEND
         DY
         4*0.25 /
         )";

tests/parser/PYACTION.cpp

@@ -44,7 +44,7 @@ C = B * 20
 SCHEDULE
 
 PYACTION Her comes an ignored comment
-)" + input_code + "<<<";
+)" + input_code + "PYEND";
 
     const std::string deck_string2 = R"(
 SCHEDULE
@@ -57,7 +57,7 @@ PYACTION
 SCHEDULE
 
 PYACTION -- Comment
-)" + input_code + "<<<" + "\nGRID";
+)" + input_code + "PYEND" + "\nGRID";
 
 
     Parser parser;