Merge pull request #518 from EspressoSystems/ak/remove-oz

Remove openzeppelin submodule

Author: akonring

.gitmodules

@@ -1,9 +1,6 @@
 [submodule "timeboost-proto/protos"]
 	path = timeboost-proto/protos
 	url = https://github.com/EspressoSystems/timeboost-proto.git
-[submodule "contracts/lib/openzeppelin-contracts-upgradeable"]
-	path = contracts/lib/openzeppelin-contracts-upgradeable
-	url = https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable
 [submodule "contracts"]
 	path = contracts
 	url = https://github.com/EspressoSystems/timeboost-contracts.git