Remove dependency on nightly compiler

.github/workflows/build.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy: 
       matrix: 
-        rust: [nightly]
+        rust: [stable]
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
@@ -23,7 +23,7 @@ jobs:
       run: |
         cargo fmt --all -- --check
         ./scripts/check_json_format.sh
-      if: matrix.rust == 'nightly'
+      if: matrix.rust == 'stable'
 
     - name: tests
       run: cargo test --all 

sdk/identity/src/device_code_flow.rs

@@ -107,9 +107,8 @@ impl<'a> DeviceCodePhaseOneResponse<'a> {
             Finish,
         }
 
-        unfold(
-            NextState::Continue,
-            async move |state: NextState| match state {
+        unfold(NextState::Continue, move |state: NextState| async move {
+            match state {
                 NextState::Continue => {
                     let uri = format!(
                         "https://login.microsoftonline.com/{}/oauth2/v2.0/token",
@@ -167,7 +166,7 @@ impl<'a> DeviceCodePhaseOneResponse<'a> {
                     }
                 }
                 NextState::Finish => None,
-            },
-        )
+            }
+        })
     }
 }

sdk/identity/src/lib.rs

@@ -1,4 +1,3 @@
-#![feature(async_closure)]
 #[macro_use]
 extern crate serde_derive;
 extern crate log;