run tests independent of user nvim setup (#39)

* chore(lua_ls): now lua_ls knows about testing functions

* spec: change way how tests srtuctured

* test(config): refactor tests

* test: utils

* refactor(utils): remove not used function

* chore(ci): add test runner

* chore(ci): remove taskfile from deps

* fix: now it works

spec/units/utils_spec.lua

@@ -0,0 +1,25 @@
+describe("gopher._utils", function()
+  local u = require "gopher._utils"
+
+  describe(".is_tbl_empty()", function()
+    it("it is empty", function()
+      assert.are.same(true, u.is_tbl_empty {})
+    end)
+
+    it("it is not empty", function()
+      assert.are.same(false, u.is_tbl_empty { first = "1", second = 2 })
+    end)
+  end)
+
+  describe(".sreq()", function()
+    it("can require existing module", function()
+      assert.are.same(require "gopher", u.sreq "gopher")
+    end)
+
+    it("cannot require non-existing module", function()
+      assert.has.errors(function()
+        u.sreq "iDontExistBtw"
+      end)
+    end)
+  end)
+end)