Make runtime dependencies looser

Avoid issues where an appplication requires a specific
version of a d3-module which is not compatible with this library

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3-simple-slider",
-  "version": "1.3.2",
+  "version": "1.3.3",
   "description": "Renders an SVG slider",
   "keywords": [
     "d3",
@@ -54,12 +54,12 @@
     "uglify-js": "^3.4.9"
   },
   "dependencies": {
-    "d3-array": "^2.0.2",
-    "d3-axis": "^1.0.12",
-    "d3-dispatch": "^1.0.5",
-    "d3-drag": "^1.2.3",
-    "d3-ease": "^1.0.5",
-    "d3-scale": "^2.1.2",
-    "d3-selection": "^1.3.2"
+    "d3-array": "^2.0.0",
+    "d3-axis": "^1.0.8",
+    "d3-dispatch": "^1.0.0",
+    "d3-drag": "^1.0.0",
+    "d3-ease": "^1.0.0",
+    "d3-scale": "^2.0.0",
+    "d3-selection": "^1.0.0"
   }
 }