added ability to use img logo instead of text logo

build/less/header.less

@@ -127,14 +127,31 @@
     padding: 0 15px;
     font-weight: 300;
     overflow: hidden;
+
+    img {
+      padding: 4px;
+      object-fit: contain;
+      margin: 0 auto;
+    }
+
     //Add support to sidebar mini by allowing the user to create
     //2 logo designs. mini and lg
     .logo-lg {
       //should be visibile when sidebar isn't collapsed
       display: block;
+
+      img {
+        max-width: 200px;
+        max-height: 50px;
+      }
     }
     .logo-mini {
       display: none;
+
+      img {
+        max-width: 50px;
+        max-height: 50px;
+      }
     }
   }
   //Navbar Brand. Alternative logo with layout-top-nav

dist/css/AdminLTE.css

@@ -308,12 +308,25 @@ a:focus {
   font-weight: 300;
   overflow: hidden;
 }
+.main-header .logo img {
+  padding: 4px;
+  object-fit: contain;
+  margin: 0 auto;
+}
 .main-header .logo .logo-lg {
   display: block;
 }
+.main-header .logo .logo-lg img {
+  max-width: 200px;
+  max-height: 50px;
+}
 .main-header .logo .logo-mini {
   display: none;
 }
+.main-header .logo .logo-mini img {
+  max-width: 50px;
+  max-height: 50px;
+}
 .main-header .navbar-brand {
   color: #fff;
 }

dist/css/alt/AdminLTE-without-plugins.css

@@ -309,12 +309,25 @@ a:focus {
   font-weight: 300;
   overflow: hidden;
 }
+.main-header .logo img {
+  padding: 4px;
+  object-fit: contain;
+  margin: 0 auto;
+}
 .main-header .logo .logo-lg {
   display: block;
 }
+.main-header .logo .logo-lg img {
+  max-width: 200px;
+  max-height: 50px;
+}
 .main-header .logo .logo-mini {
   display: none;
 }
+.main-header .logo .logo-mini img {
+  max-width: 50px;
+  max-height: 50px;
+}
 .main-header .navbar-brand {
   color: #fff;
 }