chore(style): minor docs/style cleanup
fix(circular deps): Improve error messages

As we don't check for circular dependencies before a given depth
threshold is reached we had messages like:

    "A -> B -> A -> B -> A -> ... -> A"

This commit implements a deduplication to have only:

    "A -> B -> A"
Merge pull request #101 from vicb/0514-circ

fix(circular deps): Improve error messages
style(error helper): improve readability
Merge pull request #103 from vicb/style-readability

style(error helper): improve readability
chore(travis): curl should follow links to download Dart
Merge pull request #107 from vicb/0522-travis

chore(travis): curl should follow links to download Dart
test: use the guinness lib
perf(injector): use separate structures to allow compiler optimizations
Merge pull request #111 from vicb/0529-guinness

test: use the guinness lib
test(main): fixed broken test after guinness upgrade
chore(release): 1.0.0