Temporarily disable the new custom container tests

AppVeyor is the only CI that builds MSVC 2015 and 2017, and it has now
rejected three heads of this branch. Its build log is not reachable from
where this is being worked on, so the verdict is a single bit and the cause
has to be narrowed down by bisection.

Everything else stays: the library changes, the reduced alt_string, and the
unflatten() tests. If AppVeyor passes with these three translation units
disabled, the cause is one of the six basic_json instantiations they add; if
it fails, it is in the library. Either way this commit is reverted.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

tests/src/unit-custom-array-type.cpp

@@ -17,6 +17,11 @@
 #include <type_traits>
 #include <vector>
 
+// TEMPORARY: this translation unit is disabled to narrow down an AppVeyor
+// failure on MSVC 2015/2017 whose build log this environment cannot reach.
+// The guard is removed again as soon as the cause is known.
+#if 0
+
 namespace
 {
 
@@ -148,3 +153,5 @@ TEST_CASE("array type without at()")
     CHECK(j.at(no_at_json::json_pointer("/1")) == 2);
     CHECK_THROWS_AS(j.at(no_at_json::json_pointer("/3")), no_at_json::out_of_range);
 }
+
+#endif

tests/src/unit-custom-binary-type.cpp

@@ -21,6 +21,11 @@
     #include <cstddef>
 #endif
 
+// TEMPORARY: this translation unit is disabled to narrow down an AppVeyor
+// failure on MSVC 2015/2017 whose build log this environment cannot reach.
+// The guard is removed again as soon as the cause is known.
+#if 0
+
 namespace
 {
 
@@ -77,3 +82,5 @@ TEST_CASE("binary type whose value type is not std::uint8_t")
     }
 #endif
 }
+
+#endif

tests/src/unit-custom-object-type.cpp

@@ -17,6 +17,11 @@
 #include <utility>
 #include <vector>
 
+// TEMPORARY: this translation unit is disabled to narrow down an AppVeyor
+// failure on MSVC 2015/2017 whose build log this environment cannot reach.
+// The guard is removed again as soon as the cause is known.
+#if 0
+
 namespace
 {
 
@@ -189,3 +194,5 @@ TEST_CASE("object type without key_compare")
         CHECK(no_key_compare_json(converted) == j);
     }
 }
+
+#endif