travis: build also on ppc64le architecture

The -t flag is removed because it is not supported on ppc64le
archictecture on travis and throws a error
"The input device is not a TTY"

Closes: #27

Author: sanjaymsh

.travis.yml

@@ -1,3 +1,6 @@
+arch:
+  - amd64
+  - ppc64le
 services:
   - docker
 script: .travis/run-in-docker

.travis/run-in-docker

@@ -1,8 +1,11 @@
 #! /bin/bash -x
 
+# we don't use the '-t' docker run flag because it is not supported on ppc64le
+# archictecture on Travis and throws an error "The input device is not a TTY"
+
 container_id=$(
-    docker run -d -ti -v `pwd`:/workdir:Z -u $(id -u) registry.fedoraproject.org/fedora bash
-)
+    docker run -d -i -v `pwd`:/workdir:Z -u $(id -u) registry.fedoraproject.org/fedora bash
+    )
 
 cleanup ()
 {
@@ -18,7 +21,7 @@ run_in_container ()
         uid=0
     fi
 
-    docker exec -u $uid -ti "$container_id" "$@"
+    docker exec -u $uid -i "$container_id" "$@"
 }
 
 buildrequires='