Update CHANGELOG.md

+v0.5.0
+======
+
+* Fixed bug in `mas_updateConstraints` ([Rolken](https://github.com/Rolken))
+
+Was not checking that the constraint relation was equivalent
+https://github.com/cloudkite/Masonry/pull/65
+
+* Added `mas_remakeConstraints` ([nickynick](https://github.com/nickynick))
+
+Similar `mas_updateConstraints` however instead of trying to update existing constraints it Removes all constraints previously defined and installed for the view, allowing you to provide replacements without hassle.
+
+https://github.com/cloudkite/Masonry/pull/63
+
+* Added Autoboxing for scalar/struct attribute values ([nickynick](https://github.com/nickynick))
+
+Autoboxing allows you to write equality relations and offsets by passing primitive values and structs
+```obj-c
+make.top.mas_equalTo(42);
+make.height.mas_equalTo(20);
+make.size.mas_equalTo(CGSizeMake(50, 100));
+make.edges.mas_equalTo(UIEdgeInsetsMake(10, 0, 10, 0));
+make.left.mas_equalTo(view).mas_offset(UIEdgeInsetsMake(10, 0, 10, 0));
+```
+by default these autoboxing macros are prefix with `mas_`
+If you want the unprefixed version you need to add `MAS_SHORTHAND_GLOBALS` before importing Masonry.h (ie in your Prefix.pch)
+
+https://github.com/cloudkite/Masonry/pull/62
+
+* Added ability to chain view attributes
+
+Composites are great for defining multiple attributes at once. The following example makes top, left, bottom, right equal to `superview`.
+
+```obj-c
+make.edges.equalTo(superview).insets(padding);
+```
+
+However if only three of the sides are equal to `superview` then we need to repeat quite a bit of code
+```obj-c
+make.left.equalTo(superview).insets(padding);
+make.right.equalTo(superview).insets(padding);
+make.bottom.equalTo(superview).insets(padding);
+// top needs to be equal to `otherView`
+make.top.equalTo(otherView).insets(padding);
+```
+
+This change makes it possible to chain view attributes to improve readability
+```obj-c
+make.left.right.and.bottom.equalTo(superview).insets(padding);
+make.top.equalTo(otherView).insets(padding);
+```
+
+https://github.com/cloudkite/Masonry/pull/56
+
 v0.4.0
 =======