[19.03] Bump docker-app to v0.8.0-rc1 (#335)

[19.03] Bump docker-app to v0.8.0-rc1
Upstream-commit: 00955cf7473581f0e0a0e282f029ac23581d2ea6
Component: packaging

Author: seemethere

components/packaging/plugins/app.installer

@@ -6,7 +6,7 @@ source "$(dirname "$0")/.common"
 
 GOPATH=$(go env GOPATH)
 REPO=https://github.com/docker/app.git
-COMMIT=v0.8.0-beta2
+COMMIT=v0.8.0-rc1
 DEST=${GOPATH}/src/github.com/docker/app
 
 build() {