test: remove tests that test duck typing (#314)

These tests test code that looks for relevant fields in the passed arguments
to turn into DAGNodes in both the Go and JS implementations, which looks
like the right thing to do.

Author: achingbrain

js/src/dag/put.js

@@ -65,14 +65,6 @@ module.exports = (createCommon, options) => {
       }, done)
     })
 
-    // This works because dag-cbor will just treat pbNode as a regular object
-    it.skip('should not put dag-pb node with wrong multicodec', (done) => {
-      ipfs.dag.put(pbNode, 'dag-cbor', 'sha3-512', (err) => {
-        expect(err).to.exist()
-        done()
-      })
-    })
-
     it('should put dag-cbor with default hash func (sha2-256)', (done) => {
       ipfs.dag.put(cborNode, {
         format: 'dag-cbor',
@@ -87,16 +79,6 @@ module.exports = (createCommon, options) => {
       }, done)
     })
 
-    it('should not put dag-cbor node with wrong multicodec', (done) => {
-      ipfs.dag.put(cborNode, {
-        format: 'dag-pb',
-        hashAlg: 'sha3-512'
-      }, (err) => {
-        expect(err).to.exist()
-        done()
-      })
-    })
-
     it('should return the cid', (done) => {
       ipfs.dag.put(cborNode, {
         format: 'dag-cbor',