🎉 New Source: BigCommerce (#5521)

Commits
* add new source connector BigCommerce
* all tests passed source-bigcommerce
* Documentation added
* PR number update

Co-authored-by: jsewawilson <jwilson@pebblepost.com>

airbyte-integrations/connectors/source-bigcommerce/integration_tests/acceptance.py

@@ -0,0 +1,36 @@
+#
+# MIT License
+#
+# Copyright (c) 2020 Airbyte
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+
+
+import pytest
+
+pytest_plugins = ("source_acceptance_test.plugin",)
+
+
+@pytest.fixture(scope="session", autouse=True)
+def connector_setup():
+    """ This fixture is a placeholder for external resources that acceptance test might require."""
+    # TODO: setup test dependencies if needed. otherwise remove the TODO comments
+    yield
+    # TODO: clean up test dependencies