bump 3.8.0

Extend the handle classNames, and provide props so that
upper/lower handles are easily distinguishable in CSS & React.

* Use classNames() instead of string concatenation

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rc-slider",
-  "version": "3.7.3",
+  "version": "3.8.0",
   "description": "slider ui component for react",
   "keywords": [
     "react",
@@ -42,17 +42,17 @@
     "pre-commit": "1.x",
     "rc-server": "3.x",
     "rc-tools": "4.x",
-    "react": "~0.14.0",
+    "react": "^15.2.1",
-    "react-addons-test-utils": "^0.14.0",
+    "react-addons-test-utils": "^15.2.1",
-    "react-dom": "~0.14.0"
+    "react-dom": "^15.2.1"
   },
   "pre-commit": [
     "lint"
   ],
   "dependencies": {
-    "classnames": "^2.2.1",
+    "classnames": "^2.2.5",
-    "rc-tooltip": "3.x",
+    "rc-tooltip": "^3.4.2",
-    "rc-util": "3.x",
+    "rc-util": "^3.2.1",
-    "warning": "^2.1.0"
+    "warning": "^3.0.0"
   }
 }

src/Slider.jsx

@@ -270,7 +270,7 @@ class Slider extends React.Component {
 
     const points = Object.keys(marks).map(parseFloat);
     if (step !== null) {
-      const closestStep = Math.round(val / step) * step;
+      const closestStep = (Math.round((val - min) / step) * step) + min;
       points.push(closestStep);
     }
 
@@ -337,15 +337,26 @@ class Slider extends React.Component {
     const lowerOffset = this.calcOffset(lowerBound);
 
     const handleClassName = prefixCls + '-handle';
+
+    const upperClassName = classNames({
+      [handleClassName]: true,
+      [handleClassName + '-upper']: true,
+    });
+
+    const lowerClassName = classNames({
+      [handleClassName]: true,
+      [handleClassName + '-lower']: true,
+    });
+
     const isNoTip = (step === null) || (tipFormatter === null);
 
-    const upper = cloneElement(customHandle, { className: handleClassName,
+    const upper = cloneElement(customHandle, { className: upperClassName,
         noTip: isNoTip, tipTransitionName: tipTransitionName, tipFormatter: tipFormatter,
         vertical: vertical, offset: upperOffset, value: upperBound, dragging: handle === 'upperBound' });
 
     let lower = null;
     if (range) {
-      lower = cloneElement(customHandle, { className: handleClassName,
+      lower = cloneElement(customHandle, { className: lowerClassName,
         noTip: isNoTip, tipTransitionName: tipTransitionName, tipFormatter: tipFormatter,
         vertical: vertical, offset: lowerOffset, value: lowerBound, dragging: handle === 'lowerBound' });
     }