fix(production.hbs): Vertically center logos in testimonials

#477

Author: dustinknopoff

src/styles/app.scss

@@ -618,3 +618,8 @@ blockquote::before {
 .languages {
   display: none;
 }
+
+.vertical-center {
+  display: flex;
+  align-items: center;
+}

templates/what/networking/production.hbs

@@ -5,7 +5,7 @@
             <div class="highlight"></div>
         </header>
         <div class="testimonials">
-            <div class="testimonial row">
+            <div class="testimonial row vertical-center">
                 <div class="four columns">
                     <img src="/static/images/firefox.png" />
                 </div>
@@ -21,7 +21,7 @@
                     </p>
                 </div>
             </div>
-            <div class="testimonial row">
+            <div class="testimonial row vertical-center">
                 <div class="eight columns">
                     <blockquote>
                         Rust is foundational to the Linkerd project’s technology roadmap. Its type system allows us to