Fix error message on stable

Aaron1011 · Aaron1011 · commit be9ae5e547a8 · 2019-04-25T22:42:18.000-04:00
diff --git a/tests/testsuite/pub_priv.rs b/tests/testsuite/pub_priv.rs
@@ -126,6 +126,7 @@ error: failed to parse manifest at `[..]`
 
 Caused by:
   the cargo feature `public-dependency` requires a nightly version of Cargo, but this is the `stable` channel
+See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.
 "
         )
         .run()

Original file line number	Diff line number	Diff line change
@@ -126,6 +126,7 @@ error: failed to parse manifest at `[..]`
`126`	`126`
`127`	`127`	`Caused by:`
`128`	`128`	the cargo feature `public-dependency` requires a nightly version of Cargo, but this is the `stable` channel
	`129`	`+See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.`
`129`	`130`	`"`
`130`	`131`	`)`
`131`	`132`	`.run()`