Release candidate 0.6.0

[RMHogervorst]

Description

Tasks

• spelling check
• missing link in checksum_util
• change all expect_is, to newer version of test_that:

expect_is(aa, "BaseProvider") ==
    expect_s3_class(aa, "BaseProvider")
expect_is(aa, "R6") ==
    expect_s3_class(aa, "R6")
expect_is(aa$random_element, "function") ==
    expect_type(aa$random_element, "closure")
expect_is(aa$random_element(letters), "character") ==
    expect_type(aa$random_element(letters), "character")

• see if I can improve test coverage of:

R/onload.R: 0.00%
R/ssn-provider.R: 0.00%
R/coordinate-provider.R: 35.71%
R/misc-provider.R: 42.86%
R/elements.R: 60.00%
R/person-provider-ja_JP.R: 62.50%
R/lorem-provider.R: 66.29%
R/internet-provider.R: 67.89%
R/zzz.R: 70.83%

• check vignettes

• revdepcheck

Related Issue

Closes #140

[RMHogervorst]

test coverage 89.81%