Fix 'ballot' and 'compiling' browser tests under nightwatch_local

[scottt]

The testSignature() browser test in generalTests.js would
occasionally fail due to not obtaining the correct hash and
signature values from the browser, resulting in:

✖ generalTests
   - Simple Contract (40.954s)
   Failed [equal]: ('' == '0: address: 0xCA35b7d915458EF540aDe6068dFe2F44E8fa733c')  - expected "0: address: 0xCA35b7d915458EF540aDe6068dFe2F44E8fa733c" but got: ""
       at Object.<anonymous> (/home/scottt/work/remix-0.8/remix-ide/test-browser/helpers/contracts.js:129:22)

failures.

This patch fixes it by waiting for the DOM elements with
waitForElementPresent which implicitly retries and obtaining
the correct contract instance address instead of hard coding it.

[yann300]

Thanks for the PR,
We have fixed the issue and test should pass now, we'd prefer not to modify the browser test
But that said, it makes sense to include your PR because it contains some nice improvement.
Could you remove the calls to perform(contractHelper.waitForValue('#txorigin', 10)) and keep the rest, we then merge it.
cc @LianaHus

will have a look on the evmVersion shortly

[scottt]

Could you remove the calls to perform(contractHelper.waitForValue('#txorigin', 10)) and keep the rest, we then merge it.

Done! :)

We have fixed the issue and test should pass now, we'd prefer not to modify the browser test

I believe you're referring to:
0351eb1
which makes waitForValue('#txorigin') no longer necessary by changing the way the account list is filled?

will have a look on the evmVersion shortly

I really appreciate the patch reviews and the work you guys put into this open source project.