Fix ST3 compatibility (#69)

Fixes #68

plugin.py

@@ -1,8 +1,6 @@
 from LSP.plugin import ClientConfig
 from LSP.plugin import uri_to_filename
 from LSP.plugin import WorkspaceFolder
-from LSP.plugin.core.edit import apply_workspace_edit
-from LSP.plugin.core.edit import TextEditTuple
 from LSP.plugin.core.protocol import Point
 from LSP.plugin.core.typing import Any, Callable, Dict, List, Mapping, Optional
 from LSP.plugin.core.views import point_to_offset
@@ -11,6 +9,14 @@
 import os
 import sublime
 
+try:
+    from LSP.plugin.core.edit import apply_workspace_edit
+    from LSP.plugin.core.edit import TextEditTuple
+except ImportError:
+    # Not supported in ST3
+    TextEditTuple = Any
+    pass
+
 
 def plugin_loaded():
     LspTypescriptPlugin.setup()