tests: add some basic tests

Check the the basic functionality of xmppipe:

    # https://github.com/sstephenson/bats
    # apt-get install bats
    bats test

test/10-groupchat.bats

@@ -0,0 +1,18 @@
+#!/usr/bin/env bats
+
+@test "enter MUC" {
+    xmppipe < /dev/null | grep -q "^p:available"
+}
+
+@test "send groupchat" {
+    MESSAGE="test-$$"
+    echo $MESSAGE | xmppipe -vv 2>&1 | grep -q $MESSAGE
+}
+
+@test "redirect stdout/stderr to files" {
+    TMPDIR=$(mktemp -d)
+    MESSAGE="test-$$"
+    echo $MESSAGE | xmppipe -vv > $TMPDIR/stdout 2> $TMPDIR/stderr
+    grep -q "^p:available:" $TMPDIR/stdout
+    grep -q $MESSAGE $TMPDIR/stderr
+}