Consider breaks in in_hours? calculation

Since the calculation behind `in_hours?` is optimized to avoid periods
generation, we need to take extra steps to ensure it takes breaks into
consideration.

Closes #69.

lib/biz/calculation/active.rb

@@ -8,7 +8,8 @@ def initialize(schedule, time)
       end
 
       def result
-        schedule.intervals.any? { |interval| interval.contains?(time) } &&
+        schedule.intervals.any?   { |interval| interval.contains?(time) } &&
+          schedule.breaks.none?   { |_break| _break.contains?(time) } &&
           schedule.holidays.none? { |holiday| holiday.contains?(time) }
       end
 

spec/calculation/active_spec.rb

@@ -1,18 +1,32 @@
 RSpec.describe Biz::Calculation::Active do
   subject(:calculation) {
-    described_class.new(schedule(holidays: [Date.new(2006, 1, 4)]), time)
+    described_class.new(
+      schedule(
+        breaks:   {Date.new(2006, 1, 3) => {'05:30' => '11:00'}},
+        holidays: [Date.new(2006, 1, 4)]
+      ),
+      time
+    )
   }
 
   describe '#result' do
     context 'when the time is not contained by an interval' do
-      context 'and not on a holiday' do
+      context 'and not on a break nor holiday' do
         let(:time) { Time.utc(2006, 1, 1, 6) }
 
         it 'returns false' do
           expect(calculation.result).to eq false
         end
       end
 
+      context 'and on a break' do
+        let(:time) { Time.utc(2006, 1, 3, 6) }
+
+        it 'returns false' do
+          expect(calculation.result).to eq false
+        end
+      end
+
       context 'and on a holiday' do
         let(:time) { Time.utc(2006, 1, 4, 6) }
 
@@ -31,6 +45,14 @@
         end
       end
 
+      context 'and on a break' do
+        let(:time) { Time.utc(2006, 1, 3, 10) }
+
+        it 'returns false' do
+          expect(calculation.result).to eq false
+        end
+      end
+
       context 'and on a holiday' do
         let(:time) { Time.utc(2006, 1, 4, 12) }