Merge #185

185: move slog implementation into its own module r=kinggoesgaming a=kinggoesgaming

**I'm submitting a ...**
  - [ ] bug fix
  - [ ] feature enhancement
  - [ ] deprecation or removal
  - [x] refactor

# Description
The slog impl and tests are moved into `slog_support` module

# Motivation
As part of the refactor effort, feature gated implementations need to be moved into their own modules.

# Tests
Current provided tests are passing

# Related Issue(s)
#124

src/lib.rs

@@ -174,6 +174,12 @@ cfg_if! {
     }
 }
 
+cfg_if! {
+    if #[cfg(feature = "slog")] {
+        mod slog_support;
+    }
+}
+
 cfg_if! {
     if #[cfg(feature = "std")] {
         mod std_support;
@@ -1067,18 +1073,6 @@ impl fmt::LowerHex for Uuid {
     }
 }
 
-#[cfg(feature = "slog")]
-impl slog::Value for Uuid {
-    fn serialize(
-        &self,
-        _record: &slog::Record,
-        key: slog::Key,
-        serializer: &mut slog::Serializer,
-    ) -> Result<(), slog::Error> {
-        serializer.emit_arguments(key, &format_args!("{}", self))
-    }
-}
-
 impl<'a> fmt::Display for Simple<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         fmt::LowerHex::fmt(self, f)
@@ -1181,9 +1175,6 @@ mod tests {
     use super::{NAMESPACE_X500, NAMESPACE_DNS, NAMESPACE_OID, NAMESPACE_URL};
     use super::{Uuid, UuidVariant, UuidVersion};
 
-    #[cfg(feature = "slog")]
-    use slog::{self, Drain};
-
     #[cfg(feature = "v3")]
     static FIXTURE_V3: &'static [(&'static Uuid, &'static str, &'static str)] = &[
         (
@@ -1860,12 +1851,4 @@ mod tests {
         assert!(set.contains(&id1));
         assert!(!set.contains(&id2));
     }
-
-    #[cfg(feature = "slog")]
-    #[test]
-    fn test_slog_kv() {
-        let root = slog::Logger::root(slog::Discard.fuse(), o!());
-        let u1 = test_util::new();
-        crit!(root, "test"; "u1" => u1);
-    }
 }

src/slog_support.rs

@@ -0,0 +1,28 @@
+use slog;
+use Uuid;
+
+impl slog::Value for Uuid {
+    fn serialize(
+        &self,
+        _: &slog::Record,
+        key: slog::Key,
+        serializer: &mut slog::Serializer,
+    ) -> Result<(), slog::Error> {
+        serializer.emit_arguments(key, &format_args!("{}", self))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn test_slog_kv() {
+        use slog;
+        use test_util;
+        use slog::Drain;
+
+        let root = slog::Logger::root(slog::Discard.fuse(), o!());
+        let u1 = test_util::new();
+        crit!(root, "test"; "u1" => u1);
+    }
+}