Test on stable as well

Author: eldruin

.travis.yml

@@ -2,6 +2,26 @@ language: rust
 
 matrix:
   include:
+    - env: TARGET=x86_64-unknown-linux-gnu
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      rust: stable
+
+    - env: TARGET=armebv7r-none-eabi
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      rust: stable
+
+    - env: TARGET=armebv7r-none-eabihf
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      rust: stable
+
+    - env: TARGET=armv7r-none-eabi
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      rust: stable
+
+    - env: TARGET=armv7r-none-eabihf
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      rust: stable
+
     # MSRV
     - env: TARGET=x86_64-unknown-linux-gnu
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)