increase RAM and CPU cores for Vagrant template

reduce RAM for Vagrant VMs used to run tests

build packages with multiple threads

refs #4382

Change-Id: I30ad59a6e705bafa60f5680f725b528bac5f9833
diff --git a/install_helpers/install_ndntools.py b/install_helpers/install_ndntools.py
index 9147a2b..d4d0b92 100644
--- a/install_helpers/install_ndntools.py
+++ b/install_helpers/install_ndntools.py
@@ -7,8 +7,7 @@
     print "***********************"
     os.system("git clone --depth 1 https://github.com/named-data/ndn-tools")
     os.chdir("ndn-tools")
-    os.system("./waf distclean")
     os.system("./waf configure")
-    os.system("./waf -j1")
+    os.system("./waf")
     os.system("sudo ./waf install")
     os.chdir("..")