[CMake] Require eigen 3.3

Otherwise:

…/unittest/eiquadprog-rt.cpp:180:24: error:
call of overloaded 'Matrix(int)' is ambiguous

CMakeLists.txt

@@ -40,7 +40,7 @@ PROJECT(${PROJECT_NAME} VERSION ${PROJECT_VERSION_FULL} LANGUAGES CXX)
 # ----------------------------------------------------
 # --- DEPENDENCIES -----------------------------------
 # ----------------------------------------------------
-ADD_REQUIRED_DEPENDENCY("eigen3")
+ADD_REQUIRED_DEPENDENCY("eigen3 >= 3.2.92")
 
 SET(BOOST_COMPONENTS unit_test_framework)
 SEARCH_FOR_BOOST()