Propagate 'public' field on dependencies to the index

This implements the crates.io side of rust-lang/rust#44663

This is fully backwards-compatible - 'public' will default to 'false'
for old versions of Cargo that don't include it in their manifest

Author: Aaron1011

src/git.rs

@@ -37,6 +37,7 @@ pub struct Dependency {
     pub kind: Option<DependencyKind>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub package: Option<String>,
+    pub public: bool
 }
 
 pub struct Repository {

src/models/dependency.rs

@@ -119,6 +119,7 @@ pub fn add_dependencies(
                     target: dep.target.clone(),
                     kind: dep.kind.or(Some(DependencyKind::Normal)),
                     package,
+                    public: dep.public.unwrap_or(false)
                 },
                 (
                     version_id.eq(target_version_id),

src/views/krate_publish.rs

@@ -64,6 +64,7 @@ pub struct EncodableCrateDependency {
     pub kind: Option<DependencyKind>,
     pub explicit_name_in_toml: Option<EncodableCrateName>,
     pub registry: Option<String>,
+    pub public: Option<bool>
 }
 
 impl<'de> Deserialize<'de> for EncodableCrateName {