Upgrade gradle wrapper to version 4.4.

gradle/wrapper/gradle-wrapper.properties

-#Sun Jun 18 21:47:36 EDT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-bin.zip

gradlew

@@ -33,11 +33,11 @@ DEFAULT_JVM_OPTS=""
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -155,7 +155,7 @@ if $cygwin ; then
 fi
 
 # Escape application args
-save ( ) {
+save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }