Added googletest as a submodule, validated that the changes I made succeed with clang 3.7 and gcc 5.2.

Author: glynos

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "deps/googletest"]
+	path = deps/googletest
+	url = https://github.com/google/googletest.git

CMakeLists.txt

@@ -56,7 +56,7 @@ add_subdirectory(src)
 # Testing
 if (CMAKE_PROJECT_NAME STREQUAL "Uri" OR CPP-NETLIB_BUILD_TESTS)
   enable_testing()
-  find_package(GTest REQUIRED)
+  add_subdirectory(deps/googletest)
   add_subdirectory(test)
 endif()
 

deps/googletest

@@ -1,10 +1,10 @@
-# Copyright (c) Glyn Matthews 2012, 2013.
+# Copyright (c) Glyn Matthews 2012-2016.
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at
 # http://www.boost.org/LICENSE_1_0.txt)
 
 
-include_directories(${GTEST_INCLUDE_DIRS})
+include_directories( ${gtest_SOURCE_DIR}/include)
 
 set(
   TESTS
@@ -20,8 +20,8 @@ set(
 
 foreach (test ${TESTS})
   add_executable(${test} ${test}.cpp)
-  add_dependencies(${test} network-uri)
-  target_link_libraries(${test} ${GTEST_BOTH_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT} network-uri)
+  add_dependencies(${test} network-uri gtest_main)
+  target_link_libraries(${test} ${CMAKE_THREAD_LIBS_INIT} network-uri gtest_main)
   if (OPENSSL_FOUND)
     target_link_libraries(${test} ${OPENSSL_LIBRARIES})
   endif()