Fixes and tweaks to class 2 assignments

Overall, well done, John. :sparkles: But I found a few issues when I ran your programs.

#### Exercise 5

I have to take off 2 points because the program crashes when run. :disappointed:

```
$ ruby 5_full_name_greeting.rb
What is your first name?
james
What is your middle name?
ryan
What is your last name?
sobol
5_full_name_greeting.rb:13:in `+': no implicit conversion of nil into String (TypeError)
	from 5_full_name_greeting.rb:15:in `<main>'
```

It turns out that the `.capitalize!` method returns `nil`. Once changed to `.capitalize` (i.e. no bang), the program runs fine.

#### Question 6

I have to take off 2 points because the program crashes when run. :disappointed:

```
$ ruby 6_bigger_better_favorite_number.rb
What is your favorite number?
42
6_bigger_better_favorite_number.rb:10:in `+': no implicit conversion of Float into String (TypeError)
	from 6_bigger_better_favorite_number.rb:10:in `<main>'
```

The string concatenation of `"Don't you think " + num` won't work because `num` is not a string. When changed to `"Don't you think " + num.to_s`, the program runs fine.

#### Question 8

I have to take off 1 point because the program's output isn't properly aligned. I've given you my solution to compare.

---

PS - So, um, there are 365 days in a year. :wink: