Implement Lua unit tests, this may fail

.travis.yml

@@ -1,9 +1,36 @@
-language: rust
-rust:
-  - stable
-  - beta
-  - nightly
 matrix:
-  allow_failures:
-    - rust: nightly
-cache: cargo
+  include:
+  - language: rust
+    rust:
+      - stable
+      - beta
+      - nightly
+    matrix:
+      allow_failures:
+        - rust: nightly
+    cache: cargo
+
+  # http://kiki.to/blog/2016/02/04/talk-continuous-integration-with-lua/
+  - language: python
+    env:
+      - LUA="lua=5.1"
+
+    before_install:
+      - pip install hererocks
+      - hererocks lua_install -r^ --$LUA
+      - export PATH=$PATH:$PWD/lua_install/bin
+
+    install:
+      - luarocks install luafilesystem
+      - luarocks install busted
+      - luarocks install luacov
+      - luarocks install luacov-coveralls
+      - luarocks install luacheck
+      - git submodule update --init --recursive
+
+    script:
+      - cd plugin && luacheck .
+      - lua -lluacov spec.lua
+
+    after_success:
+      - luacov-coveralls -e $TRAVIS_BUILD_DIR/lua_install