Wrote tests for 3 unittest recipes.
Wrote text for 3 testing recipes
Shortened examples
Added testing synchronous exceptions recipe
Tightened up the sync exceptions code and text
Shortened the teardown() example
Added text for recipe for testing float equality
Tightened up the code samples in the recipes
Rewrite of testing recipes based on comments by SL.
Removed book.html
Merge branch 'master' into testing

Conflicts:
	recipes/pubspec.lock
Removed method names from titles
Updated code for filtering tests recipe
Updated the first five unittest recipes based on reviewer feedback.
Merge branch 'master' into testing

Conflicts:
	recipes/pubspec.lock
Merge branch 'master' into testing

Conflicts:
	recipes/pubspec.lock
Merge branch 'testing' of https://github.com/dart-lang/cookbook into testing
Removed asciidoc header
Tweaks
Wrote recipe for consuming a Stream