v2.6-alpha

A preview release for late game upgrade changes. This release has not been heavily tested and is more likely to include regressions than a full release.

What's Changed

• Protoss AI does not make observers against Terran mines by @duran55 in #52
• Upgrade shields and air armor in Protoss lategame by @jncraton in #76

Full Changelog: v2.5...v2.6-alpha