Enable some sqlite3 tests (#1488)

* Enable some sqlite3 tests

* Fix failures

* Disable test on .NET Core 2.1

Author: slozier

Src/IronPythonTest/Cases/IronPythonCasesManifest.ini

@@ -89,6 +89,10 @@ Arguments=-X:CompilationThreshold 0 "$(TEST_FILE)" # ensure CompilationThreshold
 [IronPython.test_socket_stdlib]
 RunCondition=NOT $(IS_MONO) # TODO: figure out
 
+[IronPython.test_sqlite3_stdlib]
+IsolationLevel=PROCESS
+RunCondition=NOT $(IS_OSX) # https://github.com/IronLanguages/ironpython3/issues/1483
+
 [IronPython.test_stdconsole]
 Timeout=600000 # 10 minute timeout