Remove pubsub and replace w/ polling head of chain (#122)

* Rename geth package structs to not be prefaced with package name

* No longer need to dump schema since Travis uses migrate

* Rearrange history package

* Removed double request for receipt from block rewards

* Remove Listener + Observers and Replace w/ Polling Head

* Potential Short term Issue w/ Infura (ignore these tests for now)

pkg/fakes/blockchain.go

@@ -68,21 +68,11 @@ func (blockchain *Blockchain) GetBlockByNumber(blockNumber int64) core.Block {
 	return blockchain.blocks[blockNumber]
 }
 
-func (blockchain *Blockchain) SubscribeToBlocks(outputBlocks chan core.Block) {
-	blockchain.blocksChannel = outputBlocks
-}
-
 func (blockchain *Blockchain) AddBlock(block core.Block) {
 	blockchain.blocks[block.Number] = block
 	blockchain.blocksChannel <- block
 }
 
-func (*Blockchain) StartListening() {}
-
-func (blockchain *Blockchain) StopListening() {
-	blockchain.WasToldToStop = true
-}
-
 func (blockchain *Blockchain) SetContractStateAttribute(contractHash string, blockNumber *big.Int, attributeName string, attributeValue string) {
 	var key string
 	if blockNumber == nil {

pkg/fakes/blockchain_observer.go

@@ -1,23 +0,0 @@
-package fakes
-
-import "github.com/8thlight/vulcanizedb/pkg/core"
-
-type BlockchainObserver struct {
-	CurrentBlocks []core.Block
-	WasNotified   chan bool
-}
-
-func (observer *BlockchainObserver) LastBlock() core.Block {
-	return observer.CurrentBlocks[len(observer.CurrentBlocks)-1]
-}
-
-func NewFakeBlockchainObserver() *BlockchainObserver {
-	return &BlockchainObserver{
-		WasNotified: make(chan bool),
-	}
-}
-
-func (observer *BlockchainObserver) NotifyBlockAdded(block core.Block) {
-	observer.CurrentBlocks = append(observer.CurrentBlocks, block)
-	observer.WasNotified <- true
-}