Migrate published samples [(#2759)](#2759)

Migrate from tmp-generated-samples branch 615c08e
Remove boilerplate
Update copyright date
Blacken
Remove unused imports
Shorten docstrings
Remove CLI
Set defaults in function definition
Add link to supported types guide
Inline function arguments
Co-authored-by: Leah E. Cole <6719667+leahecole@users.noreply.github.com>

translation/samples/snippets/translate_v3_translate_text.py

@@ -0,0 +1,40 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START translate_v3_translate_text]
+from google.cloud import translate
+
+
+def sample_translate_text(project_id="[Google Cloud Project ID]"):
+    """Translating Text."""
+
+    client = translate.TranslationServiceClient()
+
+    parent = client.location_path(project_id, "global")
+
+    # Detail on supported types can be found here:
+    # https://cloud.google.com/translate/docs/supported-formats
+    response = client.translate_text(
+        parent=parent,
+        contents=["Hello, world!"],
+        mime_type="text/plain",  # mime types: text/plain, text/html
+        source_language_code="en-US",
+        target_language_code="fr",
+    )
+    # Display the translation for each input text provided
+    for translation in response.translations:
+        print(u"Translated text: {}".format(translation.translated_text))
+
+
+# [END translate_v3_translate_text]

translation/samples/snippets/translate_v3_translate_text_test.py

@@ -0,0 +1,24 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import translate_v3_translate_text
+
+PROJECT_ID = os.environ["GCLOUD_PROJECT"]
+
+
+def test_translate_text(capsys):
+    translate_v3_translate_text.sample_translate_text(PROJECT_ID)
+    out, _ = capsys.readouterr()
+    assert "Bonjour le monde" in out