Upgrade coursier to 1.1.0-M7

I've seen weird errors with the version we have that seem to be resolved
with an upgrade.

Author: smarter

vscode-dotty/package.json

@@ -51,7 +51,7 @@
     "vscode:prepublish": "npm install && ./node_modules/.bin/tsc -p ./",
     "compile": "./node_modules/.bin/tsc -p ./",
     "test": "node ./node_modules/vscode/bin/test",
-    "postinstall": "node ./node_modules/vscode/bin/install && curl -L -o out/coursier https://github.com/coursier/coursier/raw/v1.0.3/coursier"
+    "postinstall": "node ./node_modules/vscode/bin/install && curl -L -o out/coursier https://github.com/coursier/coursier/raw/v1.1.0-M7/coursier"
   },
   "extensionDependencies": [
     "daltonjorge.scala"