chore: remove step

.github/workflows/build.yml

@@ -24,28 +24,6 @@ jobs:
     - uses: actions/upload-artifact@v2
       with:
         path: "~/junit"
-  test_library_jdk9:
-    runs-on: ubuntu-latest
-    container:
-      image: openjdk:9
-    steps:
-    - uses: actions/checkout@v2
-    - name: Test
-      run: |-
-        export TERM=${TERM:-dumb}
-        ./install_crypto_deps.sh
-        ./gradlew test
-    - name: Save test results
-      run: |-
-        mkdir -p ~/junit
-        find . -type f -regex "$OUT_DIR/build/test-results/test/.*xml" -exec cp {} ~/junit/ \;
-      if: always()
-    - uses: actions/upload-artifact@v2
-      with:
-        path: "~/junit"
-    - uses: actions/upload-artifact@v2
-      with:
-        path: "~/junit"
   test_library_jdk11:
     runs-on: ubuntu-latest
     container:

src/main/java/com/gocardless/http/HttpClient.java

@@ -47,6 +47,7 @@ public class HttpClient {
     static {
         ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
         builder.put("GoCardless-Version", "2015-07-06");
+        builder.put("Accept", "application/json");
         builder.put("GoCardless-Client-Library", "gocardless-pro-java");
         builder.put("GoCardless-Client-Version", "5.20.0");
         HEADERS = builder.build();