Add build error checks

Gramex 1.x

• Recommend $YAMLURL for url.*.pattern
• Recommend $YAMLPATH for FileHandler path
• Recommend FormHandler in over DataHandler/QueryHandler
• Deploy password must be mandatory if auth: is present
• Recommend gramex.cache.open instead of pd.read_csv, etc
• Impose a max line length of 120 chars for gramex.yaml? e.g. FormHandler query: 120 char line width

Python

• Python filenames should be valid module names (no hyphens) and be in lowercase

CSS

• Eliminate style attribute
• Report instances and size of custom CSS (<style> tags as well as committed CSS files). Aim is to minimize this to improve re-use

JavaScript

• Evaluate standardjs

HTML

• HTML files should be proper HTML files. Not templates. No inline CSS