travis: running mingw build on travis ci

This commit also fixed a broken cmake dependency with unicorn

.travis/common/post-upload.sh

@@ -11,6 +11,9 @@ if [ -z $TRAVIS_TAG ]; then
     RELEASE_NAME=head
 else
     RELEASE_NAME=$(echo $TRAVIS_TAG | cut -d- -f1)
+    if [ "$NAME" = "MinGW build" ]; then
+        RELEASE_NAME="${RELEASE_NAME}-mingw"
+    fi
 fi
 
 mv "$REV_NAME" $RELEASE_NAME