add index test example

source/libs/index/test/CMakeLists.txt

+add_executable(indexTest "")
+target_sources(indexTest
+  PRIVATE 
+  "../src/index.c"  
+  "indexTests.cpp" 
+)
+target_include_directories ( indexTest
+  PUBLIC
+  "${CMAKE_SOURCE_DIR}/include/libs/index" 
+  "${CMAKE_CURRENT_SOURCE_DIR}/../inc"
+) 
+target_link_libraries (indexTest
+  os  
+  util
+  common
+  gtest_main
+  index
+)
+
+add_test(
+  NAME index_test
+  COMMAND indexTest
+)