Move events into their own module

The events were cluttering the `model` module, and so are now moved into
their own `model::event` module.

As users should not usually have to work with events all that much -
only currently in some rarely used event handlers - this change should
not be much more effort to import from.

i.e.:

```rs
use serenity::model::event::ChannelPinsAckEvent;
```
vs. the now-old:

```rs
use serenity::model::ChannelPinsAckEvent;
```

1 files changed, 1 insertions, 0 deletions

diff --git a/src/ext/cache/mod.rs b/src/ext/cache/mod.rs
index 28a8a6c..7c4d3a5 100644
--- a/src/ext/cache/mod.rs
+++ b/src/ext/cache/mod.rs
@@ -3,6 +3,7 @@ use std::collections::HashMap;
 use std::default::Default;
 use std::mem;
 use ::model::*;
+use ::model::event::*;
 
 /// A cache of all events received over a [`Connection`], where storing at least
 /// some data from the event is possible.