Added search for stereoisomers

• Added stereoisomers as a target, This will take a structure and generate structures for stereoisomers, including that caused by double bonds.

Bugfixes: using 'natoms' in steps, and continuing when not converged.

• Corrected errors handling the use of 'natoms' in the maximum number of steps allowed, e.g. '6 * natoms'.
• Correctly handle convergence failure in geomeTRIC

Bugfixes & internal changes

• Reorganized the code, moving the ASE specific parts to seamm-ase.
• Fixed formatting of output
• Fixed typos in the references

Enhancement: improved output and added to results

• Added energy, etc. to results
• Added more detail to printed output
• Fixed bugs with the GUI and with labeling substeps.

Added geomeTRIC minimizer

• Added transition states as a target
• Added the geomeTRIC minimizer
• Rationalized the convergence criteria, allowing them to be used across minimizers.

Initial working release.

Merge pull request #1 from molssi-seamm/dev

Fixing dependencies and versioneer