Update appveyor.yml

appveyor.yml

@@ -7,9 +7,19 @@ environment:
 os: Windows Server 2012
 
 install:
-  - ps: choco install maven
+  - ps: |
+      Add-Type -AssemblyName System.IO.Compression.FileSystem
+      if (!(Test-Path -Path "C:\maven" )) {
+        (new-object System.Net.WebClient).DownloadFile('https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.3.9/apache-maven-3.3.9-bin.zip', 'C:\maven-bin.zip')
+        [System.IO.Compression.ZipFile]::ExtractToDirectory("C:\maven-bin.zip", "C:\maven")
+      }
+  - cmd: SET PATH=C:\maven\apache-maven-3.3.9\bin;%JAVA_HOME%\bin;%PATH%
+  - cmd: SET MAVEN_OPTS=-XX:MaxPermSize=2g -Xmx4g
+  - cmd: SET JAVA_OPTS=-XX:MaxPermSize=2g -Xmx4g
+  - cmd: mvn --version
+  - cmd: java -version
   - ps: choco install sbt
 
 build_script:
-  - ps: mvn clean install -P travis -B -f driver/pom.xml -Dfailsafe.timeout=0
-  - ps: cd tests-scala ; sbt test
+  - mvn clean install -P travis -B -f driver/pom.xml -Dfailsafe.timeout=0
+  - cd tests-scala ; sbt test