fix(rangeSlider): step accepts a float value

Before this commit we were not able to use float values for step, to
be able to have a slider with float values.

Rounding was introduced when fixing
#477.

Now that step = 1 by default we do not need rounding automatically. If
the user is careful about all the other widgets using the same
attribute to only refine rounded values then he's fine.

src/widgets/range-slider/__tests__/range-slider-test.js

@@ -317,7 +317,7 @@ describe('rangeSlider()', () => {
 
     it('calls the refinement functions if refined with min+1', () => {
       let stats = results.disjunctiveFacets[0].stats;
-      let targetValue = Math.floor(stats.min) + 1;
+      let targetValue = stats.min + 1;
 
       let state0 = helper.state;
       widget._refine(helper, stats, [targetValue, stats.max]);
@@ -329,7 +329,7 @@ describe('rangeSlider()', () => {
 
     it('calls the refinement functions if refined with max-1', () => {
       let stats = results.disjunctiveFacets[0].stats;
-      let targetValue = Math.ceil(stats.max) - 1;
+      let targetValue = stats.max - 1;
 
       let state0 = helper.state;
       widget._refine(helper, stats, [stats.min, targetValue]);
@@ -341,7 +341,7 @@ describe('rangeSlider()', () => {
 
     it('calls the refinement functions if refined with min+1 and max-1', () => {
       let stats = results.disjunctiveFacets[0].stats;
-      let targetValue = [Math.floor(stats.min) + 1, Math.ceil(stats.max) - 1];
+      let targetValue = [stats.min + 1, stats.max - 1];
 
       let state0 = helper.state;
       widget._refine(helper, stats, targetValue);

src/widgets/range-slider/range-slider.js

@@ -137,10 +137,10 @@ function rangeSlider({
     _refine(helper, oldValues, newValues) {
       helper.clearRefinements(attributeName);
       if (newValues[0] > oldValues.min) {
-        helper.addNumericRefinement(attributeName, '>=', Math.round(newValues[0]));
+        helper.addNumericRefinement(attributeName, '>=', newValues[0]);
       }
       if (newValues[1] < oldValues.max) {
-        helper.addNumericRefinement(attributeName, '<=', Math.round(newValues[1]));
+        helper.addNumericRefinement(attributeName, '<=', newValues[1]);
       }
       helper.search();
     },