Default ctor for unique_resource implemented (#151).

include/unique_resource.h

     {
     public:
 
+        unique_resource()
+            : resource(R{}, scope_exit{[] { }}),
+            deleter(D{}, scope_exit{[] { }}),
+            execute_on_reset(false)
+        {
+        }
+
         template<class RR, class DD,
                 std::enable_if_t<(std::is_constructible_v<R ,RR> && std::is_constructible_v<D, DD>
                                 && (std::is_nothrow_constructible_v<R, RR> || std::is_constructible_v<R, RR&>)

test/CallMocks.h

     };
 
 
+    struct MoveableMock
+    {
+        static constexpr bool trompeloeil_movable_mock = true;
+
+        MAKE_CONST_MOCK1(deleter, void(Handle));
+
+        void operator()(Handle h) const
+        {
+            this->deleter(h);
+        }
+    };
+
+
     struct ThrowOnCopyMock
     {
         ThrowOnCopyMock()

test/UniqueResourceTest.cpp

     }
 }
 
+TEST_CASE("default construction", "[UniqueResource]")
+{
+    sr::unique_resource<int, MoveableMock> guard{};
+}
+
 TEST_CASE("construction with move", "[UniqueResource]")
 {
     REQUIRE_CALL(m, deleter(3));