unify studyjob json tag

[hougangliu]

studyjob json tag should keep unified style, but now camelcase and lowercase mix as below, which leads to bad UE when a user write a studyjob yaml/json file. I suggest to keep camelcase.

type StudyJobSpec struct {
	StudyName            string                `json:"studyName,omitempty"`
	Owner                string                `json:"owner,omitempty"`
	OptimizationType     OptimizationType      `json:"optimizationtype,omitempty"`
	OptimizationGoal     *float64              `json:"optimizationgoal,omitempty"`
	ObjectiveValueName   string                `json:"objectivevaluename,omitempty"`
	RequestCount         int                   `json:"requestcount,omitempty"`
	MetricsNames         []string              `json:"metricsnames,omitempty"`
	ParameterConfigs     []ParameterConfig     `json:"parameterconfigs,omitempty"`
	WorkerSpec           *WorkerSpec           `json:"workerSpec,omitempty"`
	SuggestionSpec       *SuggestionSpec       `json:"suggestionSpec,omitempty"`
	EarlyStoppingSpec    *EarlyStoppingSpec    `json:"earlyStoppingSpec,omitempty"`
	MetricsCollectorSpec *MetricsCollectorSpec `json:"metricsCollectorSpec,omitempty"`
	NasConfig            *NasConfig            `json:"nasConfig,omitempty"`
}

[xyhuang]

/assign

[jlewi]

It looks like this is fixed by #367.