Sabre v0.8.1

• Fixed tests
• Added axios (npm, GitHub) as dependency to "promisify" compiler.loadSolcVersion() properly.
• Refactored lib/client.js as we now need different data, depending on API interactions. Mage interactions more granular.
• Refactored lib/controllers/analyze.js:
• Now execution flow is largely flattened, also there is no more Promise and callback hells
  Now we have only one spinner there instead of 3 diffrent spinners.
  Added more spinnter messages to indicate execution stages more clearly. When error is encountered, current spinner message will be preserved, so we can narrow code segment.
• Refactored lib/controllers/api-version.js to follow changes in lib/client.js.
• Now text issue formatter will display N/A for issue titles, when API response contains issue with empty field.