Add assertion for count of countable
Merge pull request #41 from fritsjanb/assert_count

Added Assertion::count()
Let's test on 5.5 too
Merge pull request #42 from asm89/patch-1

Let's test on 5.5 too
Add Assertion::count test for \Countable
Merge pull request #43 from fritsjanb/assert_countable_test

Add Assertion::count test for \Countable