[CMake] Deprecation warnings on CMake versions < 3.5

[joligario]

libuv:

CMake Deprecation Warning at submodules/libuv/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.5 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.

recastnavigation: (EQEmu/recastnavigation#1)

CMake Deprecation Warning at submodules/recastnavigation/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.5 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.