Merge pull request glium#1816 from est31/release_beta6

Release 0.26.0-alpha6

Author: est31

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "glium"
-version = "0.26.0-alpha5"
+version = "0.26.0-alpha6"
 authors = ["Pierre Krieger <[email protected]>"]
 description = """
 Elegant and safe OpenGL wrapper.