Unable to import plugin project

[andreysubbotin]

Description of the bug or enhancement

• Clone project
• Try to import using IntelliJ Idea Error:

  A problem occurred configuring root project 'cuba-plugin'.
  > Could not resolve all artifacts for configuration ':classpath'.
  > Could not resolve gradle.plugin.org.jetbrains.gradle.plugin.idea-ext:gradle-idea-ext:0.5.
   Required by:
       project :
    > Could not resolve gradle.plugin.org.jetbrains.gradle.plugin.idea-ext:gradle-idea-ext:0.5.
       > Could not get resource 'https://dl.bintray.com/cuba-platform/main/gradle/plugin/org/jetbrains/gradle/plugin/idea-ext/gradle-idea-ext/0.5/gradle-idea-ext-0.5.pom'.
          > Could not GET 'https://dl.bintray.com/cuba-platform/main/gradle/plugin/org/jetbrains/gradle/plugin/idea-ext/gradle-idea-ext/0.5/gradle-idea-ext-0.5.pom'. Received status code 403 from server: Forbidden