Update CMakeLists.txt to install the cmake bindings in the right location

/usr/lib/cpprestsdk is not the correct FHS standard cmake location.
It should be placed in /usr/lib/cmake/cpprestsdk instead.

Author: LocutusOfBorg

Release/CMakeLists.txt

@@ -18,7 +18,7 @@ enable_testing()
 set(WERROR ON CACHE BOOL "Treat Warnings as Errors.")
 set(CPPREST_EXCLUDE_WEBSOCKETS OFF CACHE BOOL "Exclude websockets functionality.")
 set(CPPREST_EXCLUDE_COMPRESSION OFF CACHE BOOL "Exclude compression functionality.")
-set(CPPREST_EXPORT_DIR lib/cpprestsdk CACHE STRING "Directory to install CMake config files.")
+set(CPPREST_EXPORT_DIR lib/cmake/cpprestsdk CACHE STRING "Directory to install CMake config files.")
 set(CPPREST_INSTALL_HEADERS ON CACHE BOOL "Install header files.")
 set(CPPREST_INSTALL ON CACHE BOOL "Add install commands.")