Update in-place operations and cardinality methods to use macros

* Add a few more tests.
* Increase version to `v0.5.0`.
* Update `README` to specify `shard.yml` as the installation method.

Author: js-ojus

README.md

@@ -28,12 +28,13 @@ The original motivation for `sparsebitset` comes from a need to store custom ind
 
 ### Installation
 
-Add this line to your application's `Projectfile`:
+Add this line to your application's `shard.yml`:
 
-```crystal
-deps do
-  github "js-ojus/sparsebitset.cr"
-end
+```yaml
+dependencies:
+  sparsebitset:
+    github: js-ojus/sparsebitset.cr
+    version: ">= 0.5.0"
 ```
 
 ### Usage

shard.yml

@@ -1,5 +1,5 @@
 name: sparsebitset
-version: 0.4.1
+version: 0.5.0
 
 authors:
   - JONNALAGADDA Srinivas <js@ojuslabs.com>

spec/sparsebitset_spec.cr

@@ -715,6 +715,40 @@ describe SparseBitSet do
       end
       ary.should eq([1_u64, 10_u64, 100_u64, 1000_u64])
     end
+
+    it "should answer a full symmetric_difference" do
+      s = BitSet.new()
+      s.set(1_u64)
+      t = BitSet.new()
+      t.set(10_u64)
+      t.set(100_u64)
+      t.set(1000_u64)
+      s.symmetric_difference!(t)
+
+      ary = [] of UInt64
+      i = s.each
+      while (el = i.next) != Iterator::Stop::INSTANCE
+        ary << el as UInt64
+      end
+      ary.should eq([1_u64, 10_u64, 100_u64, 1000_u64])
+    end
+
+    it "should answer a full symmetric_difference" do
+      s = BitSet.new()
+      s.set(10_u64)
+      s.set(100_u64)
+      s.set(1000_u64)
+      t = BitSet.new()
+      t.set(1_u64)
+      s.symmetric_difference!(t)
+
+      ary = [] of UInt64
+      i = s.each
+      while (el = i.next) != Iterator::Stop::INSTANCE
+        ary << el as UInt64
+      end
+      ary.should eq([1_u64, 10_u64, 100_u64, 1000_u64])
+    end
   end
 
   describe "complement" do