Replaces ethereumjs-abi with ethers.js/abi-coder (#556)

* Replaced ethereumjs-abi with ethers.js/abi-coder

* Update package-lock file.

* Adds tests for tuple types in encodeCall.

* Remove attempt to test function types in encodeCall.

* Add a couple of tests and comments to encodeCall.

* encodeCall tests compare encoded vs decoded values, and not just verifies that the abi-coder doesnt throw.

* Parse bool types in encodeCall.

* Remove web3-utils dependency and some only's from encodeCall tests.

* Remove parsing entirely from encodeCall.

* Update a package-lock file.

* Small changes requested by @facuspagnuolo.

packages/cli/test/scripts/create.test.js

@@ -117,15 +117,10 @@ contract('create script', function([_, owner]) {
     });
 
     it('should initialize a proxy using scientific notation', async function() {
-      const proxy = await createProxy({ contractAlias, network, txParams, initMethod: 'initialize', initArgs: ["20e10"], networkFile: this.networkFile });
+      const proxy = await createProxy({ contractAlias, network, txParams, initMethod: 'initialize', initArgs: [Number("20e10")], networkFile: this.networkFile });
       (await proxy.value()).toString().should.be.eq('200000000000');
     });
 
-    it('should initialize a proxy using large number on scientific notation', async function() {
-      const proxy = await createProxy({ contractAlias, network, txParams, initMethod: 'initialize', initArgs: ["20e70"], networkFile: this.networkFile });
-      (await proxy.value()).toString().should.be.eq('2e+71');
-    });
-
     describe('warnings', function () {
       beforeEach('capturing log output', function () {
         this.logs = new CaptureLogs();