BREAKING CHANGE: Delta Pager + Large Refactor (#43)

BREAKING CHANGE: This MR addresses an underlying issue with the original implementation in regards to detecting line numbers for comments. 

As such, this is a major breaking change. The setup function signature has changed, please review the `README.md` for the new arguments. The delta pager has also been added as a dependency: https://github.com/dandavison/delta

There will be future work to implement a native solution for parsing changes and line numbers.

lua/gitlab/server.lua

@@ -0,0 +1,69 @@
+-- This module contains the logic responsible for building and starting
+-- the Golang server. The Go server is responsible for making API calls
+-- to Gitlab and returning the data
+local job      = require("gitlab.job")
+local state    = require("gitlab.state")
+local u        = require("gitlab.utils")
+local M        = {}
+
+-- Starts the Go server and call the callback provided
+M.start_server = function(callback)
+  local command = state.settings.bin
+      .. " "
+      .. state.settings.project_id
+      .. " "
+      .. state.settings.gitlab_url
+      .. " "
+      .. state.settings.port
+      .. " "
+      .. state.settings.auth_token
+      .. " "
+      .. state.settings.log_path
+
+  vim.fn.jobstart(command, {
+    on_stdout = function(job_id)
+      if job_id <= 0 then
+        vim.notify("Could not start gitlab.nvim binary", vim.log.levels.ERROR)
+      else
+        callback()
+      end
+    end,
+    on_stderr = function(_, errors)
+      local err_msg = ''
+      for _, err in ipairs(errors) do
+        if err ~= "" and err ~= nil then
+          err_msg = err_msg .. err .. "\n"
+        end
+      end
+
+      if err_msg ~= '' then vim.notify(err_msg, vim.log.levels.ERROR) end
+    end
+  })
+end
+
+
+-- Builds the Go binary
+M.build = function()
+  if not u.has_delta() then
+    vim.notify("Please install delta to use gitlab.nvim!", vim.log.levels.ERROR)
+    return
+  end
+
+  local file_path = u.current_file_path()
+  local parent_dir = vim.fn.fnamemodify(file_path, ":h:h:h:h")
+  state.settings.bin_path = parent_dir
+  state.settings.bin = parent_dir .. "/bin"
+
+  local binary_exists = vim.loop.fs_stat(state.settings.bin)
+  if binary_exists ~= nil then return end
+
+  local command = string.format("cd %s && make", state.settings.bin_path)
+  local installCode = os.execute(command .. "> /dev/null")
+  if installCode ~= 0 then
+    vim.notify("Could not install gitlab.nvim!", vim.log.levels.ERROR)
+    return false
+  end
+  return true
+end
+
+return M