Merge "Updating the iso build to CentOS 7.4"

diff --combined build/Makefile
index 4e20d3f,f1fde6a..23b7f11
--- 1/build/Makefile
--- 2/build/Makefile
+++ b/build/Makefile
@@@ -8,7 -8,7 +8,7 @@@
  ##############################################################################
  
  export USE_MASTER = ""
- export CENTDNLD = http://mirrors.cat.pdx.edu/centos/7.3.1611/isos/x86_64/CentOS-7-x86_64-DVD-1611.iso
+ export CENTDNLD = http://mirrors.cat.pdx.edu/centos/7.4.1708/isos/x86_64/CentOS-7-x86_64-DVD-1708.iso
  export RELEASE = "0"
  
  export RPM_DIST = $(shell rpm -E %dist)
@@@ -132,7 -132,7 +132,7 @@@ rpmlint
  
  $(BUILD_DIR)/python-networking-vpp.tar.gz:
        @echo "Preparing the networking-vpp RPM prerequisites"
 -      git clone $(NETVPP_REPO) $(BUILD_DIR)/python-networking-vpp-$(NETVPP_VERS)
 +      git clone $(NETVPP_REPO) -b $(NETVPP_BRANCH) $(BUILD_DIR)/python-networking-vpp-$(NETVPP_VERS)
        tar czf $(BUILD_DIR)/python-networking-vpp.tar.gz -C $(BUILD_DIR) python-networking-vpp-$(NETVPP_VERS)
  
  .PHONY: networking-vpp-rpm