Update base64 to 0.12

This removes a duplicate dependency for docs.rs.

Author: jyn514

Cargo.toml

@@ -37,7 +37,7 @@ walkdir = "2.2"
 toml = "0.5"
 fs2 = "0.4.3"
 remove_dir_all = "0.5.2"
-base64 = "0.11.0"
+base64 = "0.12.0"
 getrandom = { version = "0.1.12", features = ["std"] }
 
 [target.'cfg(unix)'.dependencies]