WIP: Server plugins via rlua (Lua 5.3) (#125)

* Add 'plugins' field to project and add rlua

* Scaffold out new SnapshotContext type (again) with plugin state

* Almost functional snapshot system with rlua proof-of-concept

* Gate plugin config on 'plugins-enabled' feature, tell Travis to test all features

* Guard remaining plugin setup code behind feature

* Bump minimum version to 1.33, should've caught this before

* Whoops, latest Rust is 1.32, not 1.33

server/tests/read_projects.rs

@@ -86,6 +86,7 @@ fn single_partition_game() {
         Project {
             name: "single-sync-point".to_string(),
             tree: root_node,
+            plugins: Vec::new(),
             serve_port: None,
             serve_place_ids: None,
             file_location: project_location.join("default.project.json"),

server/tests/snapshots.rs

@@ -8,7 +8,7 @@ use pretty_assertions::assert_eq;
 use librojo::{
     imfs::Imfs,
     project::{Project, ProjectNode},
-    rbx_snapshot::snapshot_project_tree,
+    rbx_snapshot::{SnapshotContext, snapshot_project_tree},
     snapshot_reconciler::{RbxSnapshotInstance},
 };
 
@@ -47,7 +47,11 @@ fn run_snapshot_test(path: &Path) {
     imfs.add_roots_from_project(&project)
         .expect("Could not add IMFS roots to snapshot project");
 
-    let mut snapshot = snapshot_project_tree(&imfs, &project)
+    let context = SnapshotContext {
+        plugin_context: None,
+    };
+
+    let mut snapshot = snapshot_project_tree(&context, &imfs, &project)
         .expect("Could not generate snapshot for snapshot test");
 
     if let Some(snapshot) = snapshot.as_mut() {