Use lambda expressions to reduce code

[coveralls]

Pull Request Test Coverage Report for Build 307

• 23 of 34 (67.65%) changed or added relevant lines in 6 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+2.2%) to 50.298%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/main/java/io/opentracing/contrib/jdbc/TracingConnection.java	2	3	66.67%
src/main/java/io/opentracing/contrib/jdbc/TracingPreparedStatement.java	2	3	66.67%
src/main/java/io/opentracing/contrib/jdbc/TracingDataSource.java	1	3	33.33%
src/main/java/io/opentracing/contrib/jdbc/TracingStatement.java	5	12	41.67%
<!--	Total:	23	34	67.65%	-->

Files with Coverage Reduction	New Missed Lines	%
src/main/java/io/opentracing/contrib/jdbc/JdbcTracingUtils.java	1	88.68%
src/main/java/io/opentracing/contrib/jdbc/TracingConnection.java	1	25.77%
<!--	Total:	2		-->

Totals
Change from base Build 306:	2.2%
Covered Lines:	506
Relevant Lines:	1006

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💛 - Coveralls

[malafeev]

pr branch has conflict with master

[quaff]

@malafeev conflict resolved.