Remove `-std=c++11` flag from Makefile.am
This is handled in configure.ac
@@ -215,7 +215,7 @@ check_scripts = unittest.sh
check_PROGRAMS = unittest
unittest_SOURCES = ../../tests/unittest.cpp
unittest_LDADD = libtcod.la
-unittest_CXXFLAGS = $(CXXFLAGS) -std=c++11
+unittest_CXXFLAGS = $(CXXFLAGS)
TESTS = unittest.sh
