Remove language-rust as a package dependency (#106)

* Remove language-rust as a package dependency
  Built-in support for Rust syntax is amazing thanks to tree-sitter
* Require atom >=1.33
  This is the atom release with rust syntax support built-in

Author: mehcode

package.json

@@ -11,11 +11,10 @@
     "ide"
   ],
   "package-deps": [
-    "language-rust",
     "atom-ide-ui"
   ],
   "engines": {
-    "atom": ">=1.21.0"
+    "atom": ">=1.33.0"
   },
   "dependencies": {
     "atom-languageclient": "^0.9.8",