Remove unused code & data-type 'UseManifest'

If it's unused, it shall be gone. It obfuscate what functions are
  doing and require managing extra complexity for no reason.

crates/aiken-project/src/deps.rs

@@ -133,12 +133,7 @@ impl From<&Manifest> for LocalPackages {
     }
 }
 
-pub fn download<T>(
+pub fn download<T>(event_listener: &T, root_path: &Path, config: &Config) -> Result<Manifest, Error>
-    event_listener: &T,
-    use_manifest: UseManifest,
-    root_path: &Path,
-    config: &Config,
-) -> Result<Manifest, Error>
 where
     T: EventListener,
 {
@@ -164,13 +159,7 @@ where
 
     let runtime = tokio::runtime::Runtime::new().expect("Unable to start Tokio");
 
-    let (manifest, changed) = Manifest::load(
+    let (manifest, changed) = Manifest::load(event_listener, config, root_path)?;
-        runtime.handle().clone(),
-        event_listener,
-        config,
-        use_manifest,
-        root_path,
-    )?;
 
     let local = LocalPackages::load(root_path)?;
 

crates/aiken-project/src/deps/manifest.rs

@@ -12,8 +12,6 @@ use crate::{
     telemetry::{Event, EventListener},
 };
 
-use super::UseManifest;
-
 #[derive(Deserialize, Serialize, Debug)]
 pub struct Manifest {
     pub requirements: Vec<Dependency>,
@@ -22,10 +20,8 @@ pub struct Manifest {
 
 impl Manifest {
     pub fn load<T>(
-        runtime: tokio::runtime::Handle,
         event_listener: &T,
         config: &Config,
-        use_manifest: UseManifest,
         root_path: &Path,
     ) -> Result<(Self, bool), Error>
     where
@@ -35,15 +31,10 @@ impl Manifest {
 
         // If there's no manifest (or we have been asked not to use it) then resolve
         // the versions anew
-        let should_resolve = match use_manifest {
+        let should_resolve = !manifest_path.exists();
-            _ if !manifest_path.exists() => true,
-            UseManifest::No => true,
-            UseManifest::Yes => false,
-        };
 
         if should_resolve {
-            let manifest = resolve_versions(runtime, config, None, event_listener)?;
+            let manifest = resolve_versions(config, event_listener)?;
-
             return Ok((manifest, true));
         }
 
@@ -61,13 +52,12 @@ impl Manifest {
             help: e.to_string(),
         })?;
 
-        // If the config has unchanged since the manifest was written then it is up
+        // If the config is unchanged since the manifest was written then it is up
         // to date so we can return it unmodified.
         if manifest.requirements == config.dependencies {
             Ok((manifest, false))
         } else {
-            let manifest = resolve_versions(runtime, config, Some(&manifest), event_listener)?;
+            let manifest = resolve_versions(config, event_listener)?;
-
             Ok((manifest, true))
         }
     }
@@ -96,12 +86,7 @@ pub struct Package {
     pub source: Platform,
 }
 
-fn resolve_versions<T>(
+fn resolve_versions<T>(config: &Config, event_listener: &T) -> Result<Manifest, Error>
-    _runtime: tokio::runtime::Handle,
-    config: &Config,
-    _manifest: Option<&Manifest>,
-    event_listener: &T,
-) -> Result<Manifest, Error>
 where
     T: EventListener,
 {

crates/aiken-project/src/lib.rs

@@ -27,7 +27,6 @@ use aiken_lang::{
     tipo::TypeInfo,
     IdGenerator,
 };
-use deps::UseManifest;
 use indexmap::IndexMap;
 use miette::NamedSource;
 use options::{CodeGenMode, Options};
@@ -491,12 +490,7 @@ where
     }
 
     fn compile_deps(&mut self) -> Result<(), Vec<Error>> {
-        let manifest = deps::download(
+        let manifest = deps::download(&self.event_listener, &self.root, &self.config)?;
-            &self.event_listener,
-            UseManifest::Yes,
-            &self.root,
-            &self.config,
-        )?;
 
         for package in manifest.packages {
             let lib = self.root.join(paths::build_deps_package(&package.name));