Update sqlx and refinery to newer versions

For some reason, also required rewriting database tests to deal with
tempfile deleting files after scope drop. This never used to occur,
but now it does! So now the unit tests are in a closure where the temp
file is dropped at the end of the test. Really should just use sqlx
migrations, then we can get an in-memory database.

dicebot/Cargo.toml

@@ -40,7 +40,7 @@ substring = "1.4"
 fuse-rust = "0.2"
 tonic = "0.4"
 prost = "0.7"
-tenebrous-rpc = { path = "../rpc", version = "0.1.0" }
+tenebrous-rpc = { path = "../rpc" }
 
 [dependencies.sqlx]
 version = "0.5"

rpc/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}