Remove hunter and submodules

And use external project instead.  This should make it easier to keep
our systems up to date with yocto.

Change-Id: Id2c9f3e474eebf2194eaf58b0c572f7a1421def6
diff --git a/src/gtest_main.cpp b/src/gtest_main.cpp
index 1659be8..d701498 100644
--- a/src/gtest_main.cpp
+++ b/src/gtest_main.cpp
@@ -1,4 +1,5 @@
 #include "gtest/gtest.h"
+#include "gmock/gmock.h"
 
 int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);