Auto merge of #1611 - sgrif:sg-locked-schema, r=jtgeibel

Use the `--locked-schema` flag in Diesel 1.4

This flag tells Diesel CLI to error if a command would change
`src/schema.rs`, rather than updating it. By running this in CI and
production builds, we ensure that no PR will pass which changes schema
but doesn't modify this file (which has happened in the past)

Author: bors

.diesel_version

@@ -1 +1 @@
-1.3.0
+1.4.0

.travis.yml

@@ -30,7 +30,7 @@ install:
   - cargo install --force diesel_cli --vers `cat .diesel_version` --no-default-features --features postgres && export PATH=$HOME/.cargo/bin:$PATH
 
 before_script:
-  - diesel database setup
+  - diesel database setup --locked-schema
 
 addons:
   chrome: stable

Procfile

@@ -1,2 +1,2 @@
-web: bin/diesel migration run && bin/start-nginx ./target/release/server
+web: bin/diesel migration run --locked-schema && bin/start-nginx ./target/release/server
 worker: ./target/release/update-downloads daemon 300