Remove all the excessive line height setting

h/static/styles/app.scss

@@ -184,7 +184,6 @@ $group-list-width: 225px;
 
   .masthead-heading {
     font-size: 1.1em;
-    line-height: 1em;
   }
 
   .masthead-subheading {

h/static/styles/common.scss

@@ -30,7 +30,6 @@ body {
   position: relative;
   background-color: $body-background;
   color: $text-color;
-  line-height: 1.4;
 }
 
 p {
@@ -319,8 +318,6 @@ html {
 }
 
 .tab-content {
-  line-height: 1.4;
-
   .tab-pane {
     display: none;
     &.active {

h/static/styles/forms.scss

@@ -128,7 +128,6 @@
 }
 
 .form-error {
-  line-height: 1.5;
   color: $error-color;
 }
 
@@ -166,7 +165,6 @@
 
 .form-actions-message {
   font-size: .833em;
-  line-height: 1.5;
   float: left;
   margin-top: 1em;
 }

h/static/styles/page.scss

 // Styles for full pages
 
 .page {
-  li, p {
-    line-height: 1.5;
-  }
-
   h1, h2, h3, h4, h5, h6 {
     font-weight: normal;
   }