Fixes #1702: Scratch Conference site - small edits (#1727)

Update the conference page with new banner image and small copy edits.

src/views/conference/2018/index/index.jsx

@@ -108,6 +108,9 @@ var ConferenceSplash = React.createClass({
                                 </b>{' '}
                                 <FormattedMessage id='conference-2018.sessionItem4Desc' />
                             </p>
+                            <p className='conf2018-panel-deadline'>
+                              <FormattedMessage id='conference-2018.deadline' />
+                            </p>
                         </p>
                         <a className='button mod-2018-panel' href='https://docs.google.com/forms/d/e/1FAIpQLSd7SkuQ-dfW-P3aArSQokK9GkKAUKufTVBHod_ElNIiFE9iBQ/viewform?usp=sf_link'>
                             <FormattedMessage id='conference-2018.proposal' />

src/views/conference/2018/index/index.scss

@@ -8,13 +8,17 @@
 .title-banner-image.mod-2018 {
     opacity: .75;
     margin-bottom: 1.75rem;
-    background-image: url("/images/conference/index/2017/title-banner.jpg");
+    background-image: url("/images/conference/index/2018/title-banner.jpg");
     background-position: center;
     background-size: cover;
     width: 100%;
     height: 20rem;
 }
 
+.title-banner-h1.mod-2018 {
+    line-height: 1.25em;
+}
+
 .conf2018-panel,
 .title-banner-h3.mod-2018 {
     margin: auto;
@@ -73,10 +77,6 @@ td {
         height: 10rem;
     }
 
-    .title-banner-h1.mod-2018 {
-        line-height: 1.25em;
-    }
-
     .conf2018-panel,
     .title-banner-h3.mod-2018 {
         width: initial;

src/views/conference/2018/index/l10n.json

 {
-    "conference-2018.title": "Scratch Conference 2018",
+    "conference-2018.title": "Scratch Conference 2018:",
     "conference-2018.subtitle": "The Next Generation",
     "conference-2018.dateDesc": "July 26-28, 2018 | Cambridge, MA, USA",
     "conference-2018.dateDescMore": " (with opening reception the evening of July 25)",
@@ -22,6 +22,7 @@
     "conference-2018.sessionItem4Title": "Ignite talk (5 minutes).",
     "conference-2018.sessionItem4Desc": "Share what you've been doing in a short, lively presentation.",
 
+    "conference-2018.deadline": "Deadline for proposals is February 5, 2018.",
     "conference-2018.proposal": " Submit Your Proposal",
     "conference-2018.proposalDeadline": "Deadline for proposals: February 5",
     "conference-2018.proposalAccept": "Notification of acceptance: March 1",