Update XcodeProj to 7.14.0 (#66)

**Describe your changes**
Updated XcodeProj to the latest version.

**Testing performed**
- CI

Signed-off-by: Marcin Iwanicki <marcin.iwanicki@appliwings.com>

Package.resolved

@@ -42,8 +42,17 @@
         "repositoryURL": "https://github.com/tuist/xcodeproj.git",
         "state": {
           "branch": null,
-          "revision": "f32704e01d2752bdc17cde3963bee4256c1f4df4",
-          "version": "7.8.0"
+          "revision": "81bb2bb333eafa68f8ecd8187a4bb56d51e78e97",
+          "version": "7.14.0"
+        }
+      },
+      {
+        "package": "XcodeProjCExt",
+        "repositoryURL": "https://github.com/tuist/XcodeProjCExt",
+        "state": {
+          "branch": null,
+          "revision": "21a510c225ff2bc83d5920a21d902af4b1e7e218",
+          "version": "0.1.0"
         }
       }
     ]

Package.swift

@@ -25,7 +25,7 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-tools-support-core.git", .upToNextMajor(from: "0.1.0")),
         .package(url: "https://github.com/kylef/PathKit", .upToNextMinor(from: "1.0.0")),
-        .package(url: "https://github.com/tuist/xcodeproj.git", .upToNextMajor(from: "7.8.0")),
+        .package(url: "https://github.com/tuist/xcodeproj.git", .upToNextMajor(from: "7.14.0")),
     ],
     targets: [
         .target(