Unable to find a suitable version for paper-button, please choose one by typing one of the numbers below:
1) paper-button#2.0-preview which resolved to f0ff9d8862 and is required by vaadin-upload#2.0.0-alpha2
2) paper-button#^2.0.0 which resolved to 2.0.0 and is required by angular4-polymer2
Dependency should point to paper-button#2.0 directly
Error when using paper-button 2.0 directly:
Dependency should point to paper-button#2.0 directly