variables: increase default font-size by 1px (default normal 14px)

scss/bootstrap/overrides/_variables.scss

@@ -101,11 +101,11 @@ $body-bg: $crm-background !default;
 $font-family-sans-serif:  'Helvetica Neue', Helvetica, Arial, sans-serif !default;
 $font-family-base:        'Open Sans', $font-family-sans-serif !default;
 
-$font-size-small:         12px !default;
-$font-size-base:          13px !default;
-$font-size-medium:        14px !default;
-$font-size-xs:            9px !default;
-$crm-font-size-base-unitless: 13;
+$font-size-small:         13px !default;
+$font-size-base:          14px !default;
+$font-size-medium:        15px !default;
+$font-size-xs:            10px !default;
+$crm-font-size-base-unitless: 14;
 
 $font-size-h1:            24px !default;
 $font-size-h2:            18px !default;