Deleting obsolete TimestampDocument

src/contract.TimestampDocument.sol

-// 20180612 Robert Martin-Legene <robert@nic.ar>
-// It can be difficult to feed large binary "documents" into this
-// routine, so it should be changed to accept just the checksum,
-// so we'll call this v0.1
-
-pragma solidity ^0.4.24;
-      
-contract TimestampDocument {
-
-	// This mapping is almost an "associative array"
-	mapping (bytes32 => uint) private hashes;
-
-	// Public functions
-
-	//
-	// Calculate and store the hash for a document
-	//
-	function storeDocument( string document ) public {
-		bytes32 hash = sha256(abi.encodePacked(document));
-		storeHash( hash );
-	}
-  
-	//
-	// Returns the block number a hash was first seen in.
-	// zero (0) means not found.
-	//
-	function checkDocument( string document ) public view returns (uint) {
-		return getBlock( sha256(abi.encodePacked(document)) );
-	}
-
-	// Private functions
-
-	//
-	// Stores the hash of the document in the mapping
-	// if we have not seen the hash before.
-	//
-	function storeHash( bytes32 hash ) private {
-		if ( hashes[hash] == 0 ) {
-			hashes[hash] = block.number;
-		}
-	}
-
-	//
-	// Returns the block number in which the hash was first seen,
-	// or zero (0) if never seen.
-	//
-	function getBlock( bytes32 hash ) private view returns (uint) {
-		return hashes[hash];
-	}
-}