Fixes #1728. Remove Shell-Env from Executable, use Atom's process.env instead

Atom has builtin a fix for the process.env being out of sync with
the user's actual environment variables. It is similar to how Shell-Env works
which Atom-Beautify was using. Now we no longer need it.

However, there is still an issue when running specs. Thus, Atom-Beautify
specs still patch process.env with Shell-Env.
See https://discuss.atom.io/t/specs-do-not-load-shell-environment-variables-activationhooks-core-loaded-shell-environment/44199
for details.

package.json

@@ -193,6 +193,9 @@
     "winston": "2.3.1",
     "yaml-front-matter": "3.4.0"
   },
+  "activationHooks": [
+    "core:loaded-shell-environment"
+  ],
   "activationCommands": {
     "atom-workspace": [
       "atom-beautify:help-debug-editor",

spec/beautify-languages-spec.coffee

@@ -4,6 +4,10 @@ beautifier = new Beautifiers()
 fs = require "fs"
 path = require "path"
 JsDiff = require('diff')
+shellEnv = require('shell-env')
+
+# Fix https://discuss.atom.io/t/specs-do-not-load-shell-environment-variables-activationhooks-core-loaded-shell-environment/44199
+process.env = shellEnv.sync()
 
 # Use the command `window:run-package-specs` (cmd-alt-ctrl-p) to run specs.
 #

src/beautifiers/executable.coffee

@@ -4,7 +4,6 @@ which = require('which')
 spawn = require('child_process').spawn
 path = require('path')
 semver = require('semver')
-shellEnv = require('shell-env')
 os = require('os')
 fs = require('fs')
 
@@ -324,15 +323,11 @@ class Executable
 
   @_envCache = null
   shellEnv: () ->
-    @constructor.shellEnv()
+    env = @constructor.shellEnv()
+    @debug("env", env)
+    return env
   @shellEnv: () ->
-    if @_envCache
-      return Promise.resolve(@_envCache)
-    else
-      shellEnv()
-        .then((env) =>
-          @_envCache = env
-        )
+    Promise.resolve(process.env)
 
   ###
   Like the unix which utility.