add ENV variable to control crawler execution

app/public/main.css

@@ -1,14 +1,13 @@
-.welcome-center-button { 
-  width: 100%; 
+.welcome-center-button {
+  width: 100%;
 }
 
-.next-center-button { 
+.next-center-button {
   width: 50%;
-  left: 25%; 
+  left: 25%;
 }
 
-
-.welcome-big-logo { 
+.welcome-big-logo {
   font-size: 200pt;
   background-image: url(./images/logo.png);
   background-size: contain;
@@ -16,19 +15,17 @@
   color: rgba(0, 0, 0, 0);
 }
 .no-ui-slider {
-  width: 95%
+  width: 95%;
 }
 
 .centered-element {
   margin-top: 200px;
 }
 
-
 .centered-element-small {
   margin-top: 100px;
 }
 
-
 #map {
   height: 50%;
 }
@@ -38,9 +35,9 @@ body {
   height: 100%;
   margin: 0;
   padding: 0;
-  font-family: 'Tangerine', serif;
+  font-family: "Tangerine", serif;
 }
-  
+
 #floating-panel {
   top: 10px;
   left: 25%;
@@ -49,7 +46,7 @@ body {
   padding: 5px;
   border: 1px solid #999;
   text-align: center;
-  font-family: 'Roboto', 'sans-serif';
+  font-family: "Roboto", "sans-serif";
   line-height: 30px;
   padding-left: 10px;
 }