upgrade scalafmt plugin version to fix build (#104)

diff --git a/build.gradle b/build.gradle
index 4ebd4b8..0a36515 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,10 +17,11 @@
 
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
+        gradlePluginPortal()
     }
     dependencies {
-        classpath "cz.alenkacz:gradle-scalafmt:${gradle.scalafmt.version}"
+        classpath "gradle.plugin.cz.alenkacz:gradle-scalafmt:${gradle.scalafmt.version}"
     }
 }
 
diff --git a/settings.gradle b/settings.gradle
index 2412c3e..49dc80a 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -36,7 +36,7 @@
 ]
 
 gradle.ext.scalafmt = [
-    version: '1.5.0',
+    version: '1.5.1',
     config: new File(rootProject.projectDir, '.scalafmt.conf')
 ]