InfluxDB compatibility

This release is intended for InfluxDB 2x beta as compatiblity release. The only difference from v0.3.4 is that it uses older bigquery 1.4.0 code version.

go.mod tidied

• go.mod tidied

improve module compatibility

• set go directive to 1.11 as the code does not use 1.13 lang features
• test commits with go 1.11

new connection string format

• dataset is optional connection string parameter

fixes and improvements

The changes in this release are intended fo better integration with influxdata/flux, but they are generic and do not introduce any dependency.

• minor fixes and cleanups
• added explicit authentication support in connection string
• implemented several *Context interfaces
• removed ORM extension, debug logging, vendor folder
• changed owner in package path to bonitoo-io