Use the Oswald Medium font for goal titles

The same way it's done in the official SDG icons. We're also using
uppercase with slightly smaller letter spacing for the same reason.

Even though we didn't do so in the past, we're moving the font to its
own folder inside the vendor folder and including the license file as
well in order to make it clear that these files do not follow the same
license CONSUL uses.

app/assets/stylesheets/fonts.scss

@@ -2,6 +2,7 @@
 //
 // 01. Source Sans Pro (https://www.google.com/fonts/specimen/Source+Sans+Pro)
 // 02. Lato (https://www.google.com/fonts/specimen/Lato)
+// 03. Oswald (https://fonts.google.com/specimen/Oswald)
 //
 
 // 01. Source Sans Pro
@@ -93,3 +94,34 @@
   font-weight: bold;
   font-style: normal;
 }
+
+// 03. Oswald
+// - - - - - - - - - - - - - - - - - - - - - - - - -
+
+@font-face {
+  font-family: "Oswald";
+  src: font-url("oswald/oswald-light.ttf") format("truetype");
+  font-weight: lighter;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: "Oswald";
+  src: font-url("oswald/oswald-regular.ttf") format("truetype");
+  font-weight: normal;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: "Oswald";
+  src: font-url("oswald/oswald-bold.ttf") format("truetype");
+  font-weight: bold;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: "Oswald";
+  src: font-url("oswald/oswald-medium.ttf") format("truetype");
+  font-weight: 500;
+  font-style: normal;
+}

app/assets/stylesheets/sdg/goals/show.scss

@@ -26,6 +26,13 @@
       }
     }
 
+    h1 {
+      font-family: "Oswald" !important;
+      font-weight: 500;
+      letter-spacing: -1px;
+      text-transform: uppercase;
+    }
+
     @each $code, $color in $sdg-colors {
       &.sdg-goal-#{$code} > header {
         background-color: $color;