Move from unittest-cpp to catch for unit testing. (#533)

Many thanks to @rianquinn. This should fix #495, #494 and #529.

tests/owner_tests.cpp

@@ -14,7 +14,7 @@
 //
 ///////////////////////////////////////////////////////////////////////////////
 
-#include <UnitTest++/UnitTest++.h>
+#include <catch/catch.hpp>
 
 #include <gsl/gsl>
 
@@ -24,28 +24,23 @@
 
 using namespace gsl;
 
-SUITE(owner_tests)
+void f(int* i) { *i += 1; }
+
+TEST_CASE("basic_test")
 {
-    void f(int* i) { *i += 1; }
-
-    TEST(basic_test)
-    {
-        owner<int*> p = new int(120);
-        CHECK(*p == 120);
-        f(p);
-        CHECK(*p == 121);
-        delete p;
-    }
-
-    TEST(check_pointer_constraint)
-    {
-        #ifdef CONFIRM_COMPILATION_ERRORS
-        {
-            owner<int> integerTest = 10;
-            owner<std::shared_ptr<int>> sharedPtrTest(new int(10));
-        }
-        #endif
-    }
+    owner<int*> p = new int(120);
+    CHECK(*p == 120);
+    f(p);
+    CHECK(*p == 121);
+    delete p;
 }
 
-int main(int, const char* []) { return UnitTest::RunAllTests(); }
+TEST_CASE("check_pointer_constraint")
+{
+    #ifdef CONFIRM_COMPILATION_ERRORS
+    {
+        owner<int> integerTest = 10;
+        owner<std::shared_ptr<int>> sharedPtrTest(new int(10));
+    }
+    #endif
+}