revert gcc g++ version for travis

.travis.yml

@@ -8,11 +8,9 @@ matrix:
       env: OPJ_CI_ARCH=i386
       addons:
         apt:
-          sources:
-            - ubuntu-toolchain-r-test
           packages:
-            - gcc-7-multilib
-            - g++-7-multilib
+            - gcc-multilib
+            - g++-multilib
             - libc6-i386
             - libcurl4-openssl-dev:i386
             - libpng12-dev:i386

main/source/particle/Makefile

@@ -15,7 +15,7 @@ MP = #-mp -DPARTICLE_MP
 #LNO =-LNO:opt=1:fusion=2:fission=2:fusion_peeling_limit=2048:cs1=32K:cs2=8M
 COPT = $(MP) -O3 $(LNO)  -fPIC
 
-CFLAGS = $(COPT) $(COMPFLAGS) -I. -I.. -I$(GLUT_HOME)/include -I/usr/include/c++/7/ -I../common -I../public -I../pm_shared -I../engine
+CFLAGS = $(COPT) $(COMPFLAGS) -I. -I.. -I$(GLUT_HOME)/include -I/usr/include/c++/4.8/ -I../common -I../public -I../pm_shared -I../engine
 
 POBJS =action_api.o actions.o HLRender.o opengl.o system.o
 

main/source/particles/Makefile

@@ -17,7 +17,7 @@ OS:=$(shell uname)
 #LNO =-LNO:opt=1:fusion=2:fission=2:fusion_peeling_limit=2048:cs1=32K:cs2=8M
 COPT = $(MP) -O3 $(LNO)  -fPIC
 
-CFLAGS = $(COPT) $(COMPFLAGS) -I. -I.. -I$(GLUT_HOME)/include -I/usr/include/c++/7/ -I../common -I../public -I../pm_shared -I../engine
+CFLAGS = $(COPT) $(COMPFLAGS) -I. -I.. -I$(GLUT_HOME)/include -I/usr/include/c++/4.8/ -I../common -I../public -I../pm_shared -I../engine
 
 ifeq ($(OS),Darwin)
 SLIBB = libtool -static *.o -o libparticleMP.a