ci: add clang-5.0 build job to Travis-CI

Add CI badge to README.md

Change-Id: Ieba0610e8aa05cb0dd09fc515d3c5d68a07b2af0
diff --git a/.travis.yml b/.travis.yml
index eaf279c..1aa5f44 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -101,7 +101,9 @@
       dist: trusty
       addons:
         apt:
-          sources: llvm-toolchain-trusty-3.9
+          sources:
+            - llvm-toolchain-trusty-3.9
+            - ubuntu-toolchain-r-test
           packages: clang-3.9
       env:
         - CXX=clang++-3.9
@@ -110,12 +112,26 @@
       dist: trusty
       addons:
         apt:
-          sources: llvm-toolchain-trusty-4.0
+          sources:
+            - llvm-toolchain-trusty-4.0
+            - ubuntu-toolchain-r-test
           packages: clang-4.0
       env:
         - CXX=clang++-4.0
         - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
         - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources:
+            - llvm-toolchain-trusty-5.0
+            - ubuntu-toolchain-r-test
+          packages: clang-5.0
+      env:
+        - CXX=clang++-5.0
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
 
     # macOS/clang
     # https://docs.travis-ci.com/user/osx-ci-environment/#OS-X-Version
diff --git a/README.md b/README.md
index cd3e92e..328ed76 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,20 @@
 repo-ng: Next generation of NDN repository
 ==========================================
 
-**repo-ng** is an implementation of a Named Data Networking data repository, and follows [Repo protocol](https://redmine.named-data.net/projects/repo-ng/wiki/Repo_Protocol_Specification).
+[![Build Status](https://travis-ci.org/named-data/repo-ng.svg?branch=master)](https://travis-ci.org/named-data/repo-ng)
 
-**repo-ng** uses [ndn-cxx](https://github.com/named-data/ndn-cxx) library as NDN
-development library, and uses sqlite3 as underlying storage.
+**repo-ng** is an implementation of a Named Data Networking data repository,
+and follows the [Repo protocol](https://redmine.named-data.net/projects/repo-ng/wiki/Repo_Protocol_Specification).
 
-**repo-ng** is an open source project licensed under GPL 3.0 (see `COPYING.md` for more
-detail).  We highly welcome all contributions to the repo-ng code, provided that they can licensed under GPL 3.0+ or other compatible license.
+**repo-ng** uses the [ndn-cxx](https://github.com/named-data/ndn-cxx) library
+as NDN development library, and sqlite3 as underlying storage.
+
+**repo-ng** is an open source project licensed under the GPL 3.0 (see
+`COPYING.md` for more details). We highly welcome all contributions to
+the repo-ng code, provided that they can licensed under GPL 3.0+ or other
+compatible license.
 
 See the file `INSTALL.md` for build and install instructions.
 
-Please submit any bugs or issues to [repo-ng issue tracker](https://redmine.named-data.net/projects/repo-ng/issues).
+Please submit any bugs or issues to the
+[repo-ng issue tracker](https://redmine.named-data.net/projects/repo-ng/issues).