Hipchat has documentation for installing on Debian-based distros but not on RPM-based distros like Fedora and RHEL.
However, there is an undocumented repository for RPM. The undocumented RPM repository is: https://atlassian.artifactoryonline.com/atlassian/hipchat-yum-client
To install the repository:
sudo dnf config-manager --add-repo https://atlassian.artifactoryonline.com/atlassian/hipchat-yum-client
Next, to install Hipchat 4:
sudo dnf install hipchat4 --nogpg