Revert "fix: make application/json the default content type in binary mode (cloudevents#118)"

This reverts commit 9ccfaf2.

Author: grant

lib/bindings/http/receiver_binary.js

@@ -52,11 +52,6 @@ BinaryHTTPReceiver.prototype.check = function(payload, headers) {
   // Clone and low case all headers names
   const sanityHeaders = Commons.sanityAndClone(headers);
 
-  // If no content type is provided, default to application/json
-  if (!sanityHeaders[Constants.HEADER_CONTENT_TYPE]) {
-    sanityHeaders[Constants.HEADER_CONTENT_TYPE] = Constants.MIME_JSON;
-  }
-
   // Validation Level 1
   if (!this.allowedContentTypes
     .includes(sanityHeaders[Constants.HEADER_CONTENT_TYPE])) {

test/bindings/http/receiver_binary_0_3_tests.js

@@ -144,20 +144,6 @@ describe("HTTP Transport Binding Binary Receiver for CloudEvents v0.3", () => {
       expect(receiver.check.bind(receiver, payload, attributes))
         .to.not.throw();
     });
-
-    it("No error when content-type is unspecified", () => {
-      const payload = {};
-      const attributes = {
-        "ce-type": "type",
-        "ce-specversion": "0.3",
-        "ce-source": "source",
-        "ce-id": "id"
-      };
-
-      // act and assert
-      expect(receiver.check.bind(receiver, payload, attributes))
-        .to.not.throw();
-    });
   });
 
   describe("Parse", () => {

test/bindings/http/receiver_binary_1_tests.js

@@ -130,20 +130,6 @@ describe("HTTP Transport Binding Binary Receiver for CloudEvents v1.0", () => {
         .to.throw("invalid content type");
     });
 
-    it("No error when content-type is unspecified", () => {
-      const payload = {};
-      const attributes = {
-        "ce-type": "type",
-        "ce-specversion": "1.0",
-        "ce-source": "source",
-        "ce-id": "id"
-      };
-
-      // act and assert
-      expect(receiver.check.bind(receiver, payload, attributes))
-        .to.not.throw();
-    });
-
     it("No error when all required headers are in place", () => {
       // setup
       const payload = {};