Merge pull request #240 from 0xmichalis/echidna-exercise-updates

Echidna exercise updates

Author: montyly

program-analysis/echidna/exercises/exercise1/solution.sol

@@ -1,3 +1,6 @@
+//SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity <0.8.0;
+
 import "token.sol";
 
 /// @dev to run: $ echidna-test solution.sol

program-analysis/echidna/exercises/exercise1/template.sol

@@ -1,3 +1,6 @@
+//SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity <0.8.0;
+
 import "token.sol";
 
 contract TestToken is Token {

program-analysis/echidna/exercises/exercise1/token.sol

@@ -1,4 +1,5 @@
-
+//SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity <0.8.0;
 
 contract Ownership{