Application not installed

Error : package with that name and different signature already installed.

my device already install test.apk file (Version name: 1.4). and i have create new test.apk(Versoin name: 1.5). new apk install in my device but this error show package with that name and different signature already installed.just like same error : stackoverflow.com/questions/19959890/android-app-not-install-an-existing-package-by-the-same-name-with-a-conflicting

please resolve my error

Thanks in advance

Harshad