Updates comments on example transaction
Rewords addInput/addOutput clarifications
Uses previously generated private key hex string instead
Adds varIntToNum conversion function
Adds failing test for larger transaction
Now uses varIntToNum
make wallet async functions truly async
allow fee to be set to zero
remove unnecessary deepEqual
Merge pull request #92 from dcousens/patch-1

Updates comments on example transaction
Merge pull request #97 from dcousens/reverseVarInt

Adds varIntToNum conversion function