Fix the errors the recent tidyverse update introduced

[hrbrmstr]

Version: 0.5.0
Check: examples
Result: ERROR
    Running examples in ‘docxtractr-Ex.R’ failed
    The error most likely occurred in:
    
    > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
    > ### Name: docx_extract_tbl
    > ### Title: Extract a table from a Word document
    > ### Aliases: docx_extract_tbl
    >
    > ### ** Examples
    >
    > doc3 <- read_docx(system.file("examples/data3.docx", package="docxtractr"))
    > docx_extract_tbl(doc3, 3)
    # A tibble: 6 x 2
     Foo Bar
     <chr> <chr>
    1 Aa Bb
    2 Dd Ee
    3 Gg Hh
    4 1 2
    5 Zz Jj
    6 Tt ii
    >
    > intracell_whitespace <- read_docx(system.file("examples/preserve.docx", package="docxtractr"))
    > docx_extract_tbl(intracell_whitespace, 2, preserve=FALSE)
    Error: Column 1 must be named.
    Use .name_repair to specify repair.
    Execution halted
Flavors: r-devel-linux-x86_64-debian-clang, r-devel-linux-x86_64-debian-gcc, r-patched-linux-x86_64, r-release-linux-x86_64

Version: 0.5.0
Check: examples
Result: ERROR
    Running examples in ‘docxtractr-Ex.R’ failed
    The error most likely occurred in:
    
    > ### Name: docx_extract_tbl
    > ### Title: Extract a table from a Word document
    > ### Aliases: docx_extract_tbl
    >
    > ### ** Examples
    >
    > doc3 <- read_docx(system.file("examples/data3.docx", package="docxtractr"))
    > docx_extract_tbl(doc3, 3)
    # A tibble: 6 x 2
     Foo Bar
     <chr> <chr>
    1 Aa Bb
    2 Dd Ee
    3 Gg Hh
    4 1 2
    5 Zz Jj
    6 Tt ii
    >
    > intracell_whitespace <- read_docx(system.file("examples/preserve.docx", package="docxtractr"))
    > docx_extract_tbl(intracell_whitespace, 2, preserve=FALSE)
    Error: Column 1 must be named.
    Use .name_repair to specify repair.
    Execution halted
Flavors: r-devel-linux-x86_64-fedora-clang, r-devel-linux-x86_64-fedora-gcc, r-devel-windows-ix86+x86_64, r-patched-solaris-x86, r-oldrel-windows-ix86+x86_64