Prevent std::exit(1) in tests due to ErrorGuard's destructor.

If ErrorGuard's lists have not been cleared, then it's destructor
will call std::exit(1). As that is quite unfortunate in a test, we
clear it's message stack at the end of the tests.

tests/parser/SectionTests.cpp

@@ -253,6 +253,9 @@ BOOST_AUTO_TEST_CASE(Section_ValidDecks) {
                                 "TEST8\n";
 
     BOOST_CHECK(Opm::DeckSection::checkSectionTopology( parser.parseString( with_opt, mode, errors ), parser, errors));
+    // prevent std::exit(1) in ErrorGuard's destructor!
+    errors.dump();
+    errors.clear();
 }
 
 BOOST_AUTO_TEST_CASE(Section_InvalidDecks) {
@@ -390,4 +393,7 @@ BOOST_AUTO_TEST_CASE(Section_InvalidDecks) {
                                          "TEST4\n";
 
     BOOST_CHECK(!Opm::DeckSection::checkSectionTopology( parser.parseString( missing_SCHEDULE, mode, errors ), parser, errors));
+    // prevent std::exit(1) in ErrorGuard's destructor!
+    errors.dump();
+    errors.clear();
 }

tests/parser/integration/CheckDeckValidity.cpp

@@ -102,4 +102,7 @@ BOOST_AUTO_TEST_CASE( KeywordInCorrectSection ) {
         // this fails because of the incorrect BOX keyword
         BOOST_CHECK(!Opm::checkDeck(deck, parser, parseContext, errorGuard, Opm::SectionTopology | Opm::KeywordSection));
     }
+    // prevent std::exit(1) in ErrorGuard's destructor!
+    errorGuard.dump();
+    errorGuard.clear();
 }