refactor(build): Tweak dev rockspec with format 3 features

Also normalize a bit with some niceties from other lunarmodules
projects that make it a little easier to cut releases without missing
things.

luacheck-dev-1.rockspec

@@ -1,23 +1,44 @@
-package = "luacheck"
-version = "dev-1"
+local package_name = "luacheck"
+local package_version = "dev"
+local rockspec_revision = "1"
+local github_account_name = "lunarmodules"
+local github_repo_name = package_name
+
+rockspec_format = "3.0"
+package = package_name
+version = package_version .. "-" .. rockspec_revision
+
 source = {
-   url = "git+https://github.com/lunarmodules/luacheck.git"
+  url = "git+https://github.com/" .. github_account_name .. "/" .. github_repo_name .. ".git"
 }
+
+if package_version == "dev" then source.branch = "master" else source.tag = "v" .. package_version end
+
 description = {
    summary = "A static analyzer and a linter for Lua",
    detailed = [[
-Luacheck is a command-line tool for linting and static analysis of Lua code.
-It is able to spot usage of undefined global variables, unused local variables and
-a few other typical problems within Lua programs.
-]],
+      Luacheck is a command-line tool for linting and static analysis of Lua
+      code. It is able to spot usage of undefined global variables, unused
+      local variables and a few other typical problems within Lua programs.
+   ]],
    homepage = "https://github.com/lunarmodules/luacheck",
    license = "MIT"
 }
+
 dependencies = {
    "lua >= 5.1",
    "argparse >= 0.6.0",
    "luafilesystem >= 1.6.3"
 }
+
+test_dependencies = {
+  "busted",
+}
+
+test = {
+  type = "busted",
+}
+
 build = {
    type = "builtin",
    modules = {