Disable serde1 feature in tests of rand

This feature is not applicable to rand, but is causing
issues due to a bug in average.
diff --git a/.travis.yml b/.travis.yml
index 2360b23..a0593cd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -40,7 +40,7 @@
 # - test no_std support, but only the unit tests:
 #   `cargo test --lib --no-default-features`
 # - run unit tests and doctests with all features which are available on stable:
-#   `cargo test --features=serde1,log`
+#   `cargo test --features=log`
 # - test examples:
 #   `cargo test --examples`
 # Additional tests on nightly:
@@ -64,7 +64,7 @@
         # Differs from standard script: rand_pcg features
         - cargo test --lib --no-default-features
         # TODO: add simd_support feature:
-        - cargo test --features=serde1,log
+        - cargo test --features=log
         - cargo test --examples
         - cargo test --manifest-path rand_core/Cargo.toml
         - cargo test --manifest-path rand_core/Cargo.toml --no-default-features
@@ -86,7 +86,7 @@
         # Differs from standard script: includes aarch64-apple-ios cross-build
         - cargo test --lib --no-default-features
         # TODO: add simd_support feature:
-        - cargo test --features=serde1,log
+        - cargo test --features=log
         - cargo test --examples
         - cargo test --manifest-path rand_core/Cargo.toml
         - cargo test --manifest-path rand_core/Cargo.toml --no-default-features
@@ -113,7 +113,8 @@
       script:
         # Differs from standard script: alloc feature, all features, doc build
         - cargo test --lib --no-default-features --features=alloc
-        - cargo test --all-features
+        # Excludes serde1:
+        - cargo test --features=nightly,simd_support,log
         - cargo test --benches --features=nightly
         - cargo test --examples
         - cargo test --manifest-path rand_core/Cargo.toml
@@ -207,7 +208,7 @@
 script:
   - cargo test --lib --no-default-features
   # TODO: add simd_support feature:
-  - cargo test --features=serde1,log
+  - cargo test --features=log
   - cargo test --examples
   - cargo test --manifest-path rand_core/Cargo.toml
   - cargo test --manifest-path rand_core/Cargo.toml --no-default-features
diff --git a/appveyor.yml b/appveyor.yml
index 70a8cad..c02adc8 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -34,7 +34,7 @@
 test_script:
   - cargo test --lib --no-default-features --features alloc
   # TODO: use --all-features once simd_support is sufficiently stable:
-  - cargo test --features=serde1,log
+  - cargo test --features=log
   - cargo test --benches --features=nightly
   - cargo test --examples
   - cargo test --manifest-path rand_core/Cargo.toml
diff --git a/utils/ci/script.sh b/utils/ci/script.sh
index d6338cc..cf52a6e 100644
--- a/utils/ci/script.sh
+++ b/utils/ci/script.sh
@@ -5,7 +5,7 @@
 main() {
     cross test --target $TARGET --lib --no-default-features
   # TODO: add simd_support feature:
-    cross test --target $TARGET --features=serde1,log
+    cross test --target $TARGET --features=log
     cross test --target $TARGET --examples
     cross test --target $TARGET --manifest-path rand_core/Cargo.toml
     cross test --target $TARGET --manifest-path rand_core/Cargo.toml --no-default-features