Add CI based on GitHub actions and nix

Such that CI and local dev can share the same env

Author: autozimu

.github/workflows/ci.yml

@@ -0,0 +1,12 @@
+name: ci
+
+on: [push, pull_request]
+
+jobs:
+  ci:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: actions/checkout@v1
+    - uses: cachix/install-nix-action@v10
+    # - uses: mxschmitt/action-tmate@v3
+    - run: nix-shell --run "rustup set profile default && make ci"

tests/LanguageClient_test.py

@@ -56,7 +56,7 @@ def setup(nvim):
 
 def test_textDocument_definition(nvim):
     nvim.command("edit! {}".format(PATH_MAIN_RS))
-    time.sleep(3)
+    time.sleep(10)
     nvim.funcs.cursor(3, 22)
     nvim.funcs.LanguageClient_textDocument_definition()
     time.sleep(3)