fix calculate_version script

scripts/calculate_version.sh

@@ -1,5 +1,13 @@
 #!/usr/bin/env bash
 VERSION=$(python setup.py --version)
+USAGE_MSG='Usage: BRANCH=[BRANCH] calculate_version.sh'
+
+if [ -z "$BRANCH" ]
+then
+    (>&2 echo 'You should provide branch')
+    echo $USAGE_MSG
+    exit 1
+fi
 
 
 if [ -z $VERSION ]; then
@@ -12,12 +20,12 @@ if [[ $BRANCH == 'stable' ]]; then
     exit 1
 fi
 
-git fetch --tags
+git fetch --tags > /dev/null
 
 for (( NUMBER=0; ; NUMBER++ ))
 do
     FULL_VERSION="$VERSION-$BRANCH.$NUMBER"
-    if ! [ $(git tag -l ?$FULL_VERSION) ]; then
+    if ! [ $(git tag -l | grep $FULL_VERSION) ]; then
         echo "$FULL_VERSION" | tr / -
         break
     fi