Bug Fix : Delete Elections is not guarded by Modifier

[Ronnieraj37]

Problems:

• Delete Elections function doesn't have a onlyOwner Modifier. This can make anyone to delete any election.
• There are 2 deleteElection functions both in Elections.sol and ElectionStorage.sol where one calls the other.

Elections.sol

        electionStorage.deleteElection(_election);
    }

ElectionStorage.sol

   function deleteElection (address _election) external {
        Election election = Election(_election);
        require(election.getStatus() == Election.Status.pending, "Cannot delete election after election has started");
        ...
}

Instead of adding a modifier in deleteElections we should add it inside the electionStorage and remove this function as this will just cause unnecessary loops and extra gas if modifier is added to Elections.sol.