Clean up all whitespace throughout project (#5578)

* Remove trailing whitespace from lines
* Remove trailing nad leading whitespace from files

Allows for cleaner diffs in future changes. For editors that
automatically clean up whitespace on save, will avoid unrelated line
changes in diffs.

.editorconfig

@@ -0,0 +1,7 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true

.gitignore

@@ -13,6 +13,7 @@
 MANIFEST
 coverage.*
 
+!.editorconfig
 !.gitignore
 !.travis.yml
 !.isort.cfg

.tx/config

@@ -7,4 +7,3 @@ file_filter = rest_framework/locale/<lang>/LC_MESSAGES/django.po
 source_file = rest_framework/locale/en_US/LC_MESSAGES/django.po
 source_lang = en_US
 type = PO
-

docs/api-guide/schemas.md

@@ -784,4 +784,3 @@ in [OpenAPI][open-api] format.
 [api-blueprint]: https://apiblueprint.org/
 [static-files]: https://docs.djangoproject.com/en/stable/howto/static-files/
 [named-arguments]: https://docs.djangoproject.com/en/stable/topics/http/urls/#named-groups
- 

docs/topics/3.7-announcement.md

@@ -1,4 +1,3 @@
-
 <style>
 .promo li a {
     float: left;

rest_framework/compat.py

@@ -318,4 +318,3 @@ def authenticate(request=None, **credentials):
         return authenticate(**credentials)
     else:
         return authenticate(request=request, **credentials)
-

rest_framework/static/rest_framework/css/default.css

@@ -1,4 +1,3 @@
-
 /* The navbar is fixed at >= 980px wide, so add padding to the body to prevent
 content running up underneath it. */
 

rest_framework/templates/rest_framework/docs/error.html

@@ -69,7 +69,3 @@ at <code>rest_framework/docs/error.html</code>.</p>
         <script src="{% static 'rest_framework/docs/js/jquery-1.10.2.min.js' %}"></script>
     </body>
 </html>
-
-
-
-

rest_framework/templates/rest_framework/docs/langs/javascript-intro.html

@@ -3,4 +3,3 @@
 <pre class="highlight javascript hide" data-language="javascript"><code>{% code html %}<!-- Load the JavaScript client library -->
 <script src="{% static 'rest_framework/js/coreapi-0.1.1.js' %}"></script>
 <script src="{% url 'api-docs:schema-js' %}"></script>{% endcode %}</code></pre>
-

tests/importable/__init__.py

@@ -1,2 +1 @@
-
 from rest_framework import compat  # noqa

tests/importable/test_installed.py

@@ -1,4 +1,3 @@
-
 from django.conf import settings
 from tests import importable