Add circleci build badges to the README.md

Summary: Suggested by user willianpaixao : https://github.com/facebookresearch/fastText/issues/674

Reviewed By: piotr-bojanowski

Differential Revision: D13136722

fbshipit-source-id: 4ea07342ed659d312280fd6d9087376e9c9a82d0

README.md

@@ -1,6 +1,10 @@
+# fastText
+[fastText](https://fasttext.cc/) is a library for efficient learning of word representations and sentence classification.
+
+[![CircleCI](https://circleci.com/gh/facebookresearch/fastText/tree/master.svg?style=svg)](https://circleci.com/gh/facebookresearch/fastText/tree/master)
+
 ## Table of contents
 
-* [Introduction](#introduction)
 * [Resources](#resources)
    * [Models](#models)
    * [Supplementary data](#supplementary-data)
@@ -24,10 +28,6 @@
 * [Join the fastText community](#join-the-fasttext-community)
 * [License](#license)
 
-## Introduction
-
-[fastText](https://fasttext.cc/) is a library for efficient learning of word representations and sentence classification.
-
 ## Resources
 
 ### Models