Remove CDN dependencies, copy files locally

Having requests to some CDNs on a login page is often considered Bad™,
since it can load third-party code on a sensitive page of the website.

As a side effect, this removes calls to fonts.google.com, which is a
known tracking website.

allauth_ens/static/allauth_ens/fonts/roboto.css

@@ -0,0 +1,25 @@
+/** This CSS file was taken from fonts.google.com
+ *
+ * The font "roboto" and its derivatives are under Apache license, as published
+ * here: https://www.apache.org/licenses/LICENSE-2.0
+ * The font is by Christian Robertson. Thanks!
+ */
+
+@font-face {
+  font-family: 'Roboto';
+  font-style: normal;
+  font-weight: 400;
+  src: local('Roboto'), local('Roboto-Regular'), url(roboto-regular.ttf) format('truetype');
+}
+@font-face {
+  font-family: 'Roboto';
+  font-style: normal;
+  font-weight: 700;
+  src: local('Roboto Bold'), local('Roboto-Bold'), url(roboto-bold.ttf) format('truetype');
+}
+@font-face {
+  font-family: 'Roboto Slab';
+  font-style: normal;
+  font-weight: 400;
+  src: local('Roboto Slab Regular'), local('RobotoSlab-Regular'), url(roboto-slab-regular.ttf) format('truetype');
+}

allauth_ens/templates/allauth_ens/base.html

@@ -16,19 +16,18 @@
 
   {# CSS #}
   <link rel="stylesheet"
-    href="https://fonts.googleapis.com/css?family=Roboto:400,700|Roboto+Slab:400">
+        href="{% static "allauth_ens/fonts/roboto.css" %}">
   <link rel="stylesheet"
-    href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css"
+        href="{% static "font-awesome/css/font-awesome.min.css" %}"
-    integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN"
+        >
-    crossorigin="anonymous">
   <link rel="stylesheet"
         href="{% static "allauth_ens/screen.css" %}">
 
   {# JS #}
   <script type="text/javascript"
-    src="https://code.jquery.com/jquery-3.2.1.slim.min.js"
+          src="{% static "allauth_ens/jquery-3.2.1.slim.min.js" %}"
-    integrity="sha256-k2WSCIexGzOj3Euiig+TlR8gA0EmPjuc79OEeY5L45g="
+          integrity="sha256-k2WSCIexGzOj3Euiig+TlR8gA0EmPjuc79OEeY5L45g=">
-    crossorigin="anonymous"></script>
+  </script>
   <script type="text/javascript"
           src="{% static "allauth_ens/authens.js" %}"></script>