(VDB-298) Consume Pit contract storage diffs

- Continuously parse storage diffs CSV data to read Pit contract state
- Convert ilks in database to raw bytes32 value for use in generating
  storage keys dynamically
- Persist storage diffs with block number and hash for validation

pkg/fakes/mock_header_repository.go

@@ -27,8 +27,11 @@ type MockHeaderRepository struct {
 	createOrUpdateHeaderErr                error
 	createOrUpdateHeaderPassedBlockNumbers []int64
 	createOrUpdateHeaderReturnID           int64
+	getHeaderError                         error
+	getHeaderReturnBlockHash               string
 	missingBlockNumbers                    []int64
 	headerExists                           bool
+	GetHeaderPassedBlockNumber             int64
 }
 
 func NewMockHeaderRepository() *MockHeaderRepository {
@@ -53,8 +56,9 @@ func (repository *MockHeaderRepository) CreateOrUpdateHeader(header core.Header)
 	return repository.createOrUpdateHeaderReturnID, repository.createOrUpdateHeaderErr
 }
 
-func (*MockHeaderRepository) GetHeader(blockNumber int64) (core.Header, error) {
-	return core.Header{BlockNumber: blockNumber}, nil
+func (repository *MockHeaderRepository) GetHeader(blockNumber int64) (core.Header, error) {
+	repository.GetHeaderPassedBlockNumber = blockNumber
+	return core.Header{BlockNumber: blockNumber, Hash: repository.getHeaderReturnBlockHash}, repository.getHeaderError
 }
 
 func (repository *MockHeaderRepository) MissingBlockNumbers(startingBlockNumber, endingBlockNumber int64, nodeID string) ([]int64, error) {
@@ -69,6 +73,14 @@ func (repository *MockHeaderRepository) SetHeaderExists(headerExists bool) {
 	repository.headerExists = headerExists
 }
 
+func (repository *MockHeaderRepository) SetGetHeaderError(err error) {
+	repository.getHeaderError = err
+}
+
+func (repository *MockHeaderRepository) SetGetHeaderReturnBlockHash(hash string) {
+	repository.getHeaderReturnBlockHash = hash
+}
+
 func (repository *MockHeaderRepository) AssertCreateOrUpdateHeaderCallCountAndPassedBlockNumbers(times int, blockNumbers []int64) {
 	Expect(repository.createOrUpdateHeaderCallCount).To(Equal(times))
 	Expect(repository.createOrUpdateHeaderPassedBlockNumbers).To(Equal(blockNumbers))

pkg/fakes/mock_tailer.go

@@ -0,0 +1,29 @@
+package fakes
+
+import (
+	"github.com/hpcloud/tail"
+	"gopkg.in/tomb.v1"
+)
+
+type MockTailer struct {
+	Lines      chan *tail.Line
+	TailCalled bool
+}
+
+func NewMockTailer() *MockTailer {
+	return &MockTailer{
+		Lines:      make(chan *tail.Line, 1),
+		TailCalled: false,
+	}
+}
+
+func (mock *MockTailer) Tail() (*tail.Tail, error) {
+	mock.TailCalled = true
+	fakeTail := &tail.Tail{
+		Filename: "",
+		Lines:    mock.Lines,
+		Config:   tail.Config{},
+		Tomb:     tomb.Tomb{},
+	}
+	return fakeTail, nil
+}