Remove boilerplate by enabling serde in "log" dependency

This patch adds the "serde" feature to the "log" dependency, so we can
deserialize logging levels directly into "log" types.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

lib/core/libimagrt/Cargo.toml

@@ -45,7 +45,7 @@ features = ["suggestions", "color", "wrap_help"]
 [dependencies.log]
 version = "0.4"
 default-features = false
-features = ["std"]
+features = ["std", "serde"]
 
 [dependencies.handlebars]
 version          = "^1.0.5"

lib/core/libimagrt/src/logger.rs

@@ -355,40 +355,10 @@ fn aggregate_module_settings(_matches: &ArgMatches, config: Option<&Value>)
     #[derive(Serialize, Deserialize, Debug)]
     struct LoggingModuleConfig {
         pub destinations: Option<Vec<String>>,
-        pub level: Option<LogLevel>,
+        pub level: Option<Level>,
         pub enabled: bool,
     }
 
-    #[derive(Serialize, Deserialize, Debug)]
-    enum LogLevel {
-        #[serde(rename = "trace")]
-        Trace,
-
-        #[serde(rename = "debug")]
-        Debug,
-
-        #[serde(rename = "info")]
-        Info,
-
-        #[serde(rename = "warn")]
-        Warn,
-
-        #[serde(rename = "error")]
-        Error,
-    }
-
-    impl Into<Level> for LogLevel {
-        fn into(self) -> Level {
-            match self {
-                LogLevel::Trace => Level::Trace,
-                LogLevel::Debug => Level::Debug,
-                LogLevel::Info  => Level::Info,
-                LogLevel::Warn  => Level::Warn,
-                LogLevel::Error => Level::Error,
-            }
-        }
-    }
-
     #[derive(Serialize, Deserialize, Debug)]
     struct LoggingModuleConfigMap(BTreeMap<String, LoggingModuleConfig>);