Header, cookie, and form parameters should be optional

According to the spec
(https://github.com/wordnik/swagger-spec/blob/master/versions/2.0.md#parameterObject),
only "path" parameters are required by default, while for
all other parameter types the default value is "false".
Header, cookie, and form parameters should be optional

Unittests fixed

Conflicts:
	modules/swagger-core/src/test/scala/parameter/ParameterSerializationTest.scala
Java 8 compile fix

Compilation with Java 8 had failed:
reference to Parameter is ambiguous.
both class java.lang.reflect.Parameter in java.lang.reflect
and interface com.wordnik.swagger.models.parameters.Parameter in com.wordnik.swagger.models.parameters match
Fix ScalaModelTest and compile error for Reader.java
added readme for build status
Adds defaultValue to non-body parameters

Renames devaultValue
Fixes failing test caused by model property order
Sets travisci badge to develop_2.0 branch
Merge pull request #746 from adrianbk/build-badge

Sets travisci badge to develop_2.0 branch
Adds code quality checks (test coverage & dependency convergence)
Merge pull request #745 from adrianbk/default-values

Adds defaultValue to non-body parameters
Merge pull request #747 from adrianbk/code-quality

Adds code quality checks (test coverage & dependency convergence)
added scopes
Renaming test to match maven's default test patterns
Merge pull request #750 from adrianbk/failing-tests

Renaming test to match maven's default test patterns
Merge branch 'develop_2.0' of github.com:swagger-api/swagger-core into develop_2.0
Add support for parsing allOf from a spec file. Only writing was supported.
renamed class to differentiate between implementation and definition
cleaned up error message, will further this soon
added file property