network: moves tests to fixtures
Add Justcoin Exchange to README.md
Revert "Add Justcoin Exchange to README.md"

This reverts commit 5ac49374a932bc013cfd89e6057be527acddc55f.
Add Justconi Exchange to projects using
Merge pull request #218 from dcousens/netfix

network: moves tests to fixtures
ECSignature: fixes for canonical signatures
Transaction: remove signing operations
txbuilder stuff