1.5.0 Linux RC1

Highlights from this release:

• Resolve merge conflicts through a guided flow - desktop#5400
• Clone, create, or add repositories right from the repository dropdown - desktop#5878

Linux-specific improvements:

• Update embedded Git to address libcurl incompatibilities - #79
• Update package name to github-desktop to avoid clashes with reserved packages - #80

For more information refer to the release notes on desktop.github.com.