On travis there are differences in CRs for some reason

This commit strips CRs from *.ok files and test output. Test failure used to be 
not recognized due to pipe: `cat -v` always succeeds meaning that `if ! diff 
… | cat -v` always succeeds too.

tests/test_shells/postproc.py

@@ -24,6 +24,9 @@ with codecs.open(fname, 'r', encoding='utf-8') as R:
 			if not found_cd:
 				found_cd = ('cd tests/shell/3rd' in line)
 				continue
+			line = line.translate({
+				ord('\r'): None
+			})
 			line = line.replace(pid, 'PID')
 			line = line.replace(hostname, 'HOSTNAME')
 			line = line.replace(user, 'USER')

tests/test_shells/test.sh

@@ -11,21 +11,32 @@ else
 	}
 fi
 
+check_screen_log() {
+	diff -u tests/test_shells/${1}.ok tests/shell/screen.log
+	# Explicit is better then implicit
+	return $?
+}
+
 run_test() {
 	SH="$1"
 	SESNAME="powerline-shell-test-$$"
 	screen -L -c tests/test_shells/screenrc -d -m -S "$SESNAME" \
 		env LANG=en_US.UTF-8 BINDFILE="$BINDFILE" "$@"
 	screen -S "$SESNAME" -X readreg a tests/test_shells/input.$SH
+	# Wait for screen to initialize
 	sleep 0.3s
 	screen -S "$SESNAME" -p 0 -X width 300 1
 	screen -S "$SESNAME" -p 0 -X logfile tests/shell/screen.log
 	screen -S "$SESNAME" -p 0 -X paste a
+	# Wait for screen to exit (sending command to non-existing screen session 
+	# fails; when launched instance exits corresponding session is deleted)
 	while screen -S "$SESNAME" -X blankerprg "" > /dev/null ; do
-		sleep 1s
+		sleep 0.1s
 	done
 	./tests/test_shells/postproc.py tests/shell/screen.log
-	if ! diff -u tests/test_shells/${SH}.ok tests/shell/screen.log | cat -v ; then
+	if ! check_screen_log ${SH} ; then
+		# Repeat the diff to make it better viewable in travis output
+		check_screen_log ${SH} | cat -v
 		return 1
 	fi
 	return 0