fix(module): rename to singular, fix visual bugs (#2436)

* fix(module): rename to singular, fix visual bugs

* docs(module): move migration guide

Author: iangfleming

src/components/modules/README.md renamed to src/components/module/README.md

@@ -21,7 +21,7 @@
     .bx--module__inner {
       @include layer('raised');
       background-color: $ui-01;
-      border: 1px solid $ui-04;
+      border: 1px solid transparent;
     }
 
     .bx--module__header {
@@ -34,6 +34,7 @@
     .bx--module__title {
       @include font-size('14');
       @include font-smoothing;
+      letter-spacing: 0;
       font-weight: 700;
       color: $text-01;
     }

src/components/modules/_modules.scss renamed to src/components/module/_module.scss

@@ -1,6 +1,6 @@
 ### HTML
 
-The Modules component has changed significantly! Here's one example of how the component can be composed.
+The Module component has changed significantly! Here's one example of how the component can be composed.
 
 ``` html
 <div class="bx--module bx--module--double">
@@ -17,15 +17,15 @@ The Modules component has changed significantly! Here's one example of how the c
 </div>
 ```
 
-For more examples see the `modules.html` file.
+For more examples see the `module.html` file.
 
 
 ### SCSS
 
-The `_modules.scss` file is now located at __src/components/modules/modules.scss__. You'll need to update any `@import` statements for this file to reflect this change.
+The `_module.scss` file is now located at __src/components/modules/module.scss__. You'll need to update any `@import` statements for this file to reflect this change.
 
 ```scss
-@import 'path_to_node_modules/@console/bluemix-components/src/components/modules/modules';
+@import 'path_to_node_modules/@console/bluemix-components/src/components/module/module';
 ```
 
 | Old Class                   | New Class                       | Note    |

src/components/modules/migrate-to-7.x.md renamed to src/components/module/migrate-to-7.x.md

@@ -49,7 +49,7 @@ $css--reset: false !default;
 @import '../../components/dropdown/dropdown';
 @import '../../components/loading/loading';
 @import '../../components/modal/modal';
-@import '../../components/modules/modules';
+@import '../../components/module/module';
 @import '../../components/notification/inline-notification';
 @import '../../components/notification/toast-notification';
 @import '../../components/tooltip/tooltip';