[CS] [Dependencies] [Dependency Injection] [Form] [General] Update compiler log format, remove legacy code, remove deprecated, fix docblocks/style, general Travis config, upgrade coveralls, and general fixes

[robfrawley]

Q	A
Branch?	2.0
Bug fix?	yes
New feature?	no
BC breaks?	yes
Deprecations?	no
Tests pass?	yes
Fixed tickets
License	MIT
Doc PR

This PR contains a number of 2.0 upkeep items to bring the codebase into a cleaner state, including:

• Changed AbstractCompilerPass::log() signature to variadic for string replacements; prefixed generated log messages with [liip/imagine-bundle]; and removed legacy behavior required for unsupported Symfony releases.
• Added some type hints and return types; removed unused class imports; corrected @param and @return docblock values; added @throw docblock entries as required; added explicit class properties for those that were dynamically set prior; cleaned up some simple implementations; and removed unused method-scope variables.
• Removed DependencyInjection/Factory/ChildDefinitionTrait, a holdover from logic required for unsupported Symfony releases.
• Removed Form/Type/ImageType::setDefaultOptions() and Form/Type/ImageType::getName(), both legacy behavior for older Symfony releases.
• Removed any logic specific to unsupported imagine/Imagine releases.
• Removed tests for removed code (see above); added checks to ensure compiler passes log to the container; added environment-dependant metadata reader compiler pass test.
• Cleans up the Travis build configuration to be more readable and update dependencies:
  • Upgraded satooshi/php-coveralls from the ^1.0 version constraint to ^2.0 and update build script to call renamed executable.
  • Removed double call to composer install/upgrade
  • Removes all cron conditional checks
  • Resolves @sebastianblum's comment about an incorrect conditional stopping code coverage from running properly in builds: [CI] Move the "simple-phpunit install" command to Travis install section to collapse the output #1048 (comment)

As for the last bullet point, was there a reason to include those @sebastianblum? They make the build script more confusing and AFAIK we don't use cron automated builds with this repository on Travis. Is there another reason to have them?

[alexwilson]

Really nice clean-up 👍

[sebastianblum]

great work @robfrawley thx