Add travis support

Remove realpath as Travis doesn't have it
Use bash instead of sh for build + test

Signed-off-by: Andy Goldstein <andy.goldstein@gmail.com>
(cherry picked from commit 1af01e28ef)

hack/update-generated-docs.sh

@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ARK_ROOT=$(realpath $(dirname ${BASH_SOURCE})/..)
+ARK_ROOT=$(dirname ${BASH_SOURCE})/..
 BIN=${ARK_ROOT}/_output/bin
 mkdir -p ${BIN}