Add ability to configure oauth2 security definitions

[mduesterhoeft]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 137

• 27 of 40 (67.5%) changed or added relevant lines in 4 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.3%) to 86.879%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
restdocs-openapi-gradle-plugin/src/main/kotlin/com/epages/restdocs/openapi/gradle/RestdocsOpenApiPlugin.kt	0	1	0.0%
restdocs-openapi-gradle-plugin/src/main/kotlin/com/epages/restdocs/openapi/gradle/RestdocsOpenApiTask.kt	0	3	0.0%
restdocs-openapi-gradle-plugin/src/main/kotlin/com/epages/restdocs/openapi/gradle/RestdocsOpenApiPluginExtension.kt	4	13	30.77%

Files with Coverage Reduction	New Missed Lines	%
restdocs-openapi-gradle-plugin/src/main/kotlin/com/epages/restdocs/openapi/gradle/OpenApi20Generator.kt	2	98.34%

Totals
Change from base Build 132:	-0.3%
Covered Lines:	1119
Relevant Lines:	1288

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💛 - Coveralls