sylabs/singularity: Singularity 3.0.3 release candidate 2

Howdy Singularity containerizers! Announcing the first release candidate of Singularity version 3.0.3! This point release for the 3.0 series contains several important bug fixes and a few improvements. Here are the highlights: Bind paths in singularity.conf are properly parsed and applied at runtime Singularity runtime will properly fail if singularity.conf file is not owned by the root user Several improvements to RPM packaging including using golang from epel, improved support for Fedora, and avoiding overwriting conf file on new RPM install Unprivileged --contain option now properly mounts devpts on older kernels Uppercase proxy environment variables are now rightly respected Please kick the tires on it when you get a chance and ensure that it works as advertised. As always, please report any bugs to: https://github.com/sylabs/singularity/issues/new And if you think that you've discovered a security vulnerability please report it to: security@sylabs.i