Update Rust to 1.21.0

library/rust

@@ -1,14 +1,14 @@
-# this file is generated via https://github.com/rust-lang-nursery/docker-rust/blob/7683fbd450e413543c814eabc013fae38747cdcc/generate-stackbrew-library.sh
+# this file is generated via https://github.com/rust-lang-nursery/docker-rust/blob/6424dba66086036a0cedde6c86c281d892305f95/generate-stackbrew-library.sh
 
 Maintainers: Steven Fackler <[email protected]> (@sfackler)
 GitRepo: https://github.com/rust-lang-nursery/docker-rust.git
 
-Tags: 1.20.0-stretch, 1-stretch, 1.20-stretch, stretch, 1.20.0, 1, 1.20, latest
+Tags: 1.21.0-stretch, 1-stretch, 1.21-stretch, stretch, 1.21.0, 1, 1.21, latest
 Architectures: amd64, arm32v7, arm64v8, i386
-GitCommit: bf30ee63bff0a381ccacdb86436bb7da5dc9c853
-Directory: 1.20.0/stretch
+GitCommit: 6424dba66086036a0cedde6c86c281d892305f95
+Directory: 1.21.0/stretch
 
-Tags: 1.20.0-jessie, 1-jessie, 1.20-jessie, jessie
+Tags: 1.21.0-jessie, 1-jessie, 1.21-jessie, jessie
 Architectures: amd64, arm32v7, arm64v8, i386
-GitCommit: bf30ee63bff0a381ccacdb86436bb7da5dc9c853
-Directory: 1.20.0/jessie
+GitCommit: 6424dba66086036a0cedde6c86c281d892305f95
+Directory: 1.21.0/jessie