Add upgrade tests

tests/integration/test_upgrade.py

@@ -0,0 +1,52 @@
+import pytest
+
+
+@pytest.mark.upgrade
+def test_category_sorted_alphabetically_with_directive(pipenv_instance_private_pypi):
+    with pipenv_instance_private_pypi() as p:
+        with open(p.pipfile_path, "w") as f:
+            contents = """
+[pipenv]
+sort_pipfile = true
+
+[packages]
+zipp = "*"
+six = 1.11
+colorama = "*"
+atomicwrites = "*"
+            """.strip()
+            f.write(contents)
+
+        package_name = "six"
+        c = p.pipenv(f"upgrade {package_name}")
+        assert c.returncode == 0
+        assert list(p.pipfile["packages"].keys()) == [
+            "atomicwrites",
+            "colorama",
+            "six",
+            "zipp",
+        ]
+
+
+@pytest.mark.upgrade
+def test_category_not_sorted_without_directive(pipenv_instance_private_pypi):
+    with pipenv_instance_private_pypi() as p:
+        with open(p.pipfile_path, "w") as f:
+            contents = """
+[packages]
+zipp = "*"
+six = 1.11
+colorama = "*"
+atomicwrites = "*"
+            """.strip()
+            f.write(contents)
+
+        package_name = "six"
+        c = p.pipenv(f"upgrade {package_name}")
+        assert c.returncode == 0
+        assert list(p.pipfile["packages"].keys()) == [
+            "zipp",
+            "six",
+            "colorama",
+            "atomicwrites",
+        ]