ether and shouldFail tests (#1513)

* Added ether tests.

* Added shouldFail base function and tests.

* Updated test descriptions.

* Reduced gas limit on out-of-gas tests.

contracts/mocks/Failer.sol

@@ -0,0 +1,22 @@
+pragma solidity ^0.4.24;
+
+contract Failer {
+    uint256[] private array;
+
+    function dontFail() public pure {
+    }
+
+    function failWithRevert() public pure {
+        revert();
+    }
+
+    function failWithThrow() public pure {
+        assert(false);
+    }
+
+    function failWithOutOfGas() public {
+        for (uint256 i = 0; i < 2**200; ++i) {
+            array.push(i);
+        }
+    }
+}