Release a new version

[yoshoku]

Many functions have been updated and added. I would appreciate it if you could consider for releasing a new version.

• Fixed:
  • Fix bug on performing vector-matrix product
  • Fix bug on searching UPCAST on blas_char method
  • Fix bug on performing complex vector product
  • Suppress debug message on qr method
  • Remove driver option on LU factorization methods
  • Fix dirver option of solve method
• Changed:
  • Update eigh method to handle generalized eigenvalue problem
  • Update eigh method to specify indices of eigenvalues and eigenvectors
  • Update Travis CI config file to perform tests on Ruby ver. 2.5
• Added:
  • Add lu method
  • Add cholesky method
  • Add ldl method
  • Add basic tests

[masa16]

Thank you for many contributions. May I add your name to author list in README.md ?

[yoshoku]

Sure! It is an honor.

[yoshoku]

Thank you so much!