Add and use text skin for Button component

src/Sulu/Bundle/AdminBundle/Resources/js/components/Button/README.md

@@ -45,6 +45,19 @@ const onClick = () => {
     alert('Clicked this nice button, congrats!');
 };
 
+<Button
+    skin="text"
+    onClick={onClick}>
+    Click me dude
+</Button>
+```
+
+```javascript
+const onClick = () => {
+    /* do click things */
+    alert('Clicked this nice button, congrats!');
+};
+
 <Button
     skin="icon"
     icon="su-plus"

src/Sulu/Bundle/AdminBundle/Resources/js/components/Button/button.scss

@@ -17,6 +17,9 @@ $secondaryDisabledColor: $silver;
 $linkColor: $black;
 $linkDisabledColor: $silverChalice;
 
+$textColor: $black;
+$textDisabledColor: $silverChalice;
+
 $iconFontSize: 14px;
 $iconBackgroundColorActive: $doveGray;
 $iconBackgroundColorHover: $mercury;
@@ -111,6 +114,28 @@ $iconColorActive: $white;
     }
 }
 
+.text {
+    padding: 0;
+    border: 0;
+    background: transparent;
+    cursor: pointer;
+    font-size: $fontSize;
+    color: $textColor;
+
+    .button-icon + .text {
+        margin-left: 10px;
+    }
+
+    .dropdown-icon {
+        margin-left: 10px;
+        font-size: $dropdownFontSize;
+    }
+
+    &:disabled {
+        color: $textDisabledColor;
+    }
+}
+
 .icon {
     background: none;
     min-width: 30px;

src/Sulu/Bundle/AdminBundle/Resources/js/components/Button/tests/Button.test.js

@@ -23,6 +23,10 @@ test('Should render with skin link', () => {
     expect(render(<Button skin="link" />)).toMatchSnapshot();
 });
 
+test('Should render with skin text', () => {
+    expect(render(<Button skin="text" />)).toMatchSnapshot();
+});
+
 test('Should render with skin icon', () => {
     expect(render(<Button skin="icon" />)).toMatchSnapshot();
 });

src/Sulu/Bundle/AdminBundle/Resources/js/components/Button/tests/__snapshots__/Button.test.js.snap

@@ -100,6 +100,13 @@ exports[`Should render with skin secondary and dropdown icon 1`] = `
 </button>
 `;
 
+exports[`Should render with skin text 1`] = `
+<button
+  class="button text"
+  type="button"
+/>
+`;
+
 exports[`should render disabled with skin secondary 1`] = `
 <button
   class="button secondary"

src/Sulu/Bundle/AdminBundle/Resources/js/components/Button/types.js

@@ -1,3 +1,3 @@
 // @flow
 
-export type ButtonSkin = 'primary' | 'secondary' | 'link' | 'icon';
+export type ButtonSkin = 'primary' | 'secondary' | 'link' | 'text' | 'icon';

src/Sulu/Bundle/SnippetBundle/Resources/js/views/SnippetAreas/SnippetAreas.js

@@ -107,7 +107,7 @@ class SnippetAreas extends React.Component<ViewProps> {
                                                 <Button
                                                     className={snippetAreasStyles.titleButton}
                                                     onClick={this.handleSnippetClick}
-                                                    skin="link"
+                                                    skin="text"
                                                     value={defaultUuid}
                                                 >
                                                     {defaultTitle}

src/Sulu/Bundle/SnippetBundle/Resources/js/views/SnippetAreas/tests/__snapshots__/SnippetAreas.test.js.snap

@@ -77,7 +77,7 @@ exports[`Render snippet areas with data as table 1`] = `
             class="cellContent"
           >
             <button
-              class="button link titleButton"
+              class="button text titleButton"
               type="button"
             >
               <span