Merge remote-tracking branch 'origin/4.1.x'

# Conflicts:
#	pom.xml

spring-cloud-build-tools/src/main/resources/checkstyle.xml

@@ -190,5 +190,21 @@
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.TypecastParenPadCheck"/>
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAfterCheck"/>
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAroundCheck"/>
+		<module name="com.puppycrawl.tools.checkstyle.checks.regexp.RegexpSinglelineJavaCheck">
+			<property name="id" value="toLowerCaseWithoutLocale"/>
+			<property name="format" value="\.toLowerCase\(\)"/>
+			<property name="maximum" value="0"/>
+			<property name="message"
+					  value="String.toLowerCase() should be String.toLowerCase(Locale.ROOT)"/>
+			<property name="ignoreComments" value="true"/>
+		</module>
+		<module name="com.puppycrawl.tools.checkstyle.checks.regexp.RegexpSinglelineJavaCheck">
+			<property name="id" value="toUpperCaseWithoutLocale"/>
+			<property name="format" value="\.toUpperCase\(\)"/>
+			<property name="maximum" value="0"/>
+			<property name="message"
+					  value="String.toUpperCase() should be String.toUpperCase(Locale.ROOT)"/>
+			<property name="ignoreComments" value="true"/>
+		</module>
 	</module>
 </module>