[Composer] Add abraham/twitteroauth dependency

- Add vendor to .gitignore
- Add install step for addons

.gitignore

@@ -22,3 +22,6 @@ report/
 
 #ignore smarty cache
 /view/smarty3/compiled/
+
+#ignore Composer folder
+vendor/

INSTALL.txt

@@ -4,9 +4,10 @@
 
 To install all addons using git, cd into your top level Friendica directory and
 
-git clone https://github.com/friendica/friendica-addons.git addon
+	git clone https://github.com/friendica/friendica-addons.git addon
+	util/composer.phar install -d addon
 
-This will clone the entire repository in a directory called addon.  They can now be activated in the addons section of your admin panel.
+This will clone the entire repository in a directory called addon. They can now be activated in the addons section of your admin panel.
 
 ********************
 * Install Manually *

composer.json

@@ -0,0 +1,10 @@
+{
+    "name": "friendica/friendica-addons",
+    "description": "Addons library for Friendica",
+    "type": "library",
+    "require": {
+        "abraham/twitteroauth": "^0.7.4"
+    },
+    "license": "3-clause BSD license",
+    "minimum-stability": "stable"
+}

composer.lock

@@ -0,0 +1,72 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "341c2ca2f25177375c65577f7e5d7369",
+    "packages": [
+        {
+            "name": "abraham/twitteroauth",
+            "version": "0.7.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/abraham/twitteroauth.git",
+                "reference": "c6f9e692552dd037b2324ed0dfa28a4e60875acf"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/abraham/twitteroauth/zipball/c6f9e692552dd037b2324ed0dfa28a4e60875acf",
+                "reference": "c6f9e692552dd037b2324ed0dfa28a4e60875acf",
+                "shasum": ""
+            },
+            "require": {
+                "ext-curl": "*",
+                "php": "^5.6 || ^7.0"
+            },
+            "require-dev": {
+                "phpmd/phpmd": "~2.6",
+                "phpunit/phpunit": "~5.7",
+                "squizlabs/php_codesniffer": "~3.0"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Abraham\\TwitterOAuth\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Abraham Williams",
+                    "email": "abraham@abrah.am",
+                    "homepage": "https://abrah.am",
+                    "role": "Developer"
+                }
+            ],
+            "description": "The most popular PHP library for use with the Twitter OAuth REST API.",
+            "homepage": "https://twitteroauth.com",
+            "keywords": [
+                "Twitter API",
+                "Twitter oAuth",
+                "api",
+                "oauth",
+                "rest",
+                "social",
+                "twitter"
+            ],
+            "time": "2017-06-30T22:02:01+00:00"
+        }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": []
+}